from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm, mm
from reportlab.lib import colors
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether, PageBreak
)
from reportlab.platypus.flowables import Flowable
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.graphics.shapes import Drawing, Rect, String, Line, Arrow
from reportlab.graphics.charts.flowcharts import BasicFlowChart
from reportlab.graphics import renderPDF
import textwrap

# ─── Document setup ─────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    "/tmp/workspace/surgery-paper/MBBS_Surgery_Answers.pdf",
    pagesize=A4,
    rightMargin=2*cm, leftMargin=2*cm,
    topMargin=2*cm, bottomMargin=2*cm,
    title="MBBS Phase 3 Part 2 – Surgery Paper 1 – Model Answers",
    author="Reference: Bailey & Love, Sabiston, Robbins Pathology"
)

W, H = A4
styles = getSampleStyleSheet()

# ─── Custom styles ───────────────────────────────────────────────────────────
BLUE  = colors.HexColor("#1A3A6B")
LBLUE = colors.HexColor("#E8F0FA")
GOLD  = colors.HexColor("#B8860B")
RED   = colors.HexColor("#8B0000")
TEAL  = colors.HexColor("#006666")
LGREY = colors.HexColor("#F5F5F5")
GREEN = colors.HexColor("#1A5E3A")

def sty(name, **kw):
    s = styles[name].clone(name+"_custom_"+str(id(kw)))
    for k, v in kw.items():
        setattr(s, k, v)
    return s

cover_title = sty("Title", fontSize=20, textColor=BLUE, leading=26,
                  spaceAfter=6, alignment=TA_CENTER)
cover_sub   = sty("Normal", fontSize=13, textColor=GOLD, leading=18,
                  alignment=TA_CENTER, spaceAfter=4)
cover_note  = sty("Normal", fontSize=9, textColor=colors.grey,
                  alignment=TA_CENTER, spaceAfter=2)

q_style = sty("Heading1", fontSize=13, textColor=colors.white, leading=18,
              spaceAfter=4, spaceBefore=14)
sub_style = sty("Heading2", fontSize=11, textColor=TEAL, leading=15,
                spaceBefore=10, spaceAfter=3)
body = sty("Normal", fontSize=9.5, leading=14, spaceAfter=4,
           alignment=TA_JUSTIFY)
bullet_style = sty("Normal", fontSize=9.5, leading=13, leftIndent=14,
                   firstLineIndent=-10, spaceAfter=2, alignment=TA_JUSTIFY)
bold_body = sty("Normal", fontSize=9.5, leading=13, spaceAfter=3,
                fontName="Helvetica-Bold")
caption = sty("Normal", fontSize=8.5, textColor=colors.grey,
              alignment=TA_CENTER, spaceAfter=4)
italic_note = sty("Normal", fontSize=9, textColor=colors.grey,
                  fontName="Helvetica-Oblique", spaceAfter=3)
ref_style = sty("Normal", fontSize=8, textColor=colors.grey,
                fontName="Helvetica-Oblique", spaceAfter=2)

def B(t): return f"<b>{t}</b>"
def I(t): return f"<i>{t}</i>"
def bullet(t): return Paragraph(f"&#x2022;  {t}", bullet_style)
def numbered(n, t): return Paragraph(f"<b>{n}.</b>  {t}", bullet_style)
def sub(t): return Paragraph(t, sub_style)
def p(t): return Paragraph(t, body)
def sp(h=0.18): return Spacer(1, h*cm)

def q_header(qnum, marks, title):
    """Blue banner for question header."""
    data = [[Paragraph(f"<b>Q{qnum}. {title}</b>  <font color='#FFD700'>[{marks} Marks]</font>",
                       sty("Normal", fontSize=11, textColor=colors.white,
                           fontName="Helvetica-Bold", leading=16))]]
    t = Table(data, colWidths=[W - 4*cm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), BLUE),
        ("TOPPADDING", (0,0), (-1,-1), 8),
        ("BOTTOMPADDING", (0,0), (-1,-1), 8),
        ("LEFTPADDING", (0,0), (-1,-1), 10),
        ("RIGHTPADDING", (0,0), (-1,-1), 10),
        ("ROUNDEDCORNERS", [4,4,4,4]),
    ]))
    return t

def sub_header(t):
    data = [[Paragraph(f"<b>{t}</b>",
                       sty("Normal", fontSize=10, textColor=TEAL,
                           fontName="Helvetica-Bold", leading=14))]]
    tbl = Table(data, colWidths=[W - 4*cm])
    tbl.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), LBLUE),
        ("TOPPADDING", (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING", (0,0), (-1,-1), 8),
        ("LINEBELOW", (0,0), (-1,-1), 1, TEAL),
    ]))
    return tbl

def info_box(title, items, bg=LGREY, tc=BLUE):
    rows = [[Paragraph(f"<b>{title}</b>",
                       sty("Normal", fontSize=9.5, textColor=tc,
                           fontName="Helvetica-Bold"))]]
    for it in items:
        rows.append([bullet(it)])
    t = Table(rows, colWidths=[W - 4*cm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), bg),
        ("TOPPADDING", (0,0), (-1,-1), 3),
        ("BOTTOMPADDING", (0,0), (-1,-1), 3),
        ("LEFTPADDING", (0,0), (-1,-1), 8),
        ("BOX", (0,0), (-1,-1), 0.8, tc),
    ]))
    return t

def two_col_table(left_title, left_items, right_title, right_items):
    """Two-column comparison table."""
    lrows = [Paragraph(f"<b>{left_title}</b>",
                       sty("Normal", fontName="Helvetica-Bold",
                           textColor=colors.white, fontSize=9))]
    for it in left_items:
        lrows.append(Paragraph(f"• {it}", sty("Normal", fontSize=8.5, leading=12)))
    rrows = [Paragraph(f"<b>{right_title}</b>",
                       sty("Normal", fontName="Helvetica-Bold",
                           textColor=colors.white, fontSize=9))]
    for it in right_items:
        rrows.append(Paragraph(f"• {it}", sty("Normal", fontSize=8.5, leading=12)))
    max_r = max(len(lrows), len(rrows))
    while len(lrows) < max_r: lrows.append(Paragraph("", body))
    while len(rrows) < max_r: rrows.append(Paragraph("", body))
    data = [[l, r] for l, r in zip(lrows, rrows)]
    cw = (W - 4*cm - 0.3*cm) / 2
    t = Table(data, colWidths=[cw, cw])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (0,0), TEAL),
        ("BACKGROUND", (1,0), (1,0), BLUE),
        ("BACKGROUND", (0,1), (0,-1), LGREY),
        ("BACKGROUND", (1,1), (1,-1), colors.HexColor("#EEF3FF")),
        ("TOPPADDING", (0,0), (-1,-1), 3),
        ("BOTTOMPADDING", (0,0), (-1,-1), 3),
        ("LEFTPADDING", (0,0), (-1,-1), 6),
        ("BOX", (0,0), (-1,-1), 0.5, colors.grey),
        ("INNERGRID", (0,0), (-1,-1), 0.3, colors.grey),
    ]))
    return t

# ─── Flowchart drawing helper ────────────────────────────────────────────────
def flowchart_burns():
    """Simple emergency burns flowchart using Table-based boxes."""
    steps = [
        ("STEP 1", "Scene Safety + Remove patient from source", BLUE),
        ("STEP 2", "Primary Survey: Airway-Breathing-Circulation (ABC)", TEAL),
        ("STEP 3", "Assess % TBSA burn (Rule of Nines) & Depth", RED),
        ("STEP 4", "Establish IV access — 2 large bore peripheral cannulae", colors.HexColor("#4B0082")),
        ("STEP 5", "Fluid resuscitation: Parkland Formula\n4 mL × weight(kg) × %TBSA = volume in 24h\n(Half in first 8 h; rest in next 16 h)", GREEN),
        ("STEP 6", "Analgesia: IV morphine titrated + anti-emetic", colors.HexColor("#8B4513")),
        ("STEP 7", "Wound care: Cool (15-25°C water, 20 min), cover with cling film", TEAL),
        ("STEP 8", "Monitor: Urinary catheter — target 0.5 mL/kg/h adults; 1 mL/kg/h children", BLUE),
        ("STEP 9", "Nasogastric tube, Tetanus prophylaxis, Transfer if indicated", RED),
    ]
    flowable_rows = []
    for num, text, col in steps:
        row_data = [[
            Paragraph(f"<b>{num}</b>",
                      sty("Normal", fontSize=9, textColor=colors.white,
                          fontName="Helvetica-Bold", alignment=TA_CENTER)),
            Paragraph(text.replace("\n", "<br/>"),
                      sty("Normal", fontSize=9, leading=13))
        ]]
        t = Table(row_data, colWidths=[1.8*cm, W-4*cm-1.8*cm-0.4*cm])
        t.setStyle(TableStyle([
            ("BACKGROUND", (0,0), (0,-1), col),
            ("BACKGROUND", (1,0), (1,-1), LGREY),
            ("TOPPADDING", (0,0), (-1,-1), 5),
            ("BOTTOMPADDING", (0,0), (-1,-1), 5),
            ("LEFTPADDING", (0,0), (-1,-1), 6),
            ("BOX", (0,0), (-1,-1), 0.5, colors.grey),
            ("VALIGN", (0,0), (-1,-1), "MIDDLE"),
        ]))
        flowable_rows.append(t)
        flowable_rows.append(sp(0.05))
    return flowable_rows

def rule_of_nines_table():
    data = [
        [Paragraph("<b>Body Part</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white)),
         Paragraph("<b>Adults</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white)),
         Paragraph("<b>Children (Lund-Browder)</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white))],
        ["Head & Neck", "9%", "18% at birth → decreases with age"],
        ["Each Upper Limb", "9%", "9%"],
        ["Anterior Trunk", "18%", "18%"],
        ["Posterior Trunk", "18%", "18%"],
        ["Each Lower Limb", "18%", "14% at birth → increases with age"],
        ["Genitalia/Perineum", "1%", "1%"],
    ]
    cw = (W-4*cm)/3
    t = Table(data, colWidths=[cw, cw, cw])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,0), BLUE),
        ("TEXTCOLOR", (0,0), (-1,0), colors.white),
        ("BACKGROUND", (0,1), (-1,-1), LGREY),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [LGREY, colors.white]),
        ("TOPPADDING", (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING", (0,0), (-1,-1), 6),
        ("BOX", (0,0), (-1,-1), 0.8, BLUE),
        ("INNERGRID", (0,0), (-1,-1), 0.3, colors.grey),
        ("FONTNAME", (0,1), (-1,-1), "Helvetica"),
        ("FONTSIZE", (0,1), (-1,-1), 9),
    ]))
    return t

def thyroiditis_table():
    data = [
        [Paragraph("<b>Type</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white)),
         Paragraph("<b>Features</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white)),
         Paragraph("<b>Management</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white))],
        ["Hashimoto's\n(Chronic lymphocytic)",
         "Autoimmune; Anti-TPO & anti-TG Ab +ve; hypothyroidism; Hurthle cell change; germinal centres",
         "Levothyroxine replacement; monitor TSH"],
        ["De Quervain's\n(Subacute granulomatous)",
         "Viral etiology; painful tender goitre; fever; ESR ↑; RAIU ↓; transient thyrotoxicosis",
         "NSAIDs/Aspirin; Prednisolone 40mg/d for severe; β-blockers if symptomatic thyrotoxicosis"],
        ["Painless/Silent\n(Subacute lymphocytic)",
         "Autoimmune; postpartum variant; no pain; transient thyrotoxicosis then hypothyroidism",
         "Observation; β-blockers if needed; levothyroxine if hypothyroid persists"],
        ["Riedel's\n(Fibrous thyroiditis)",
         "Dense fibrosis; 'iron hard' goitre; may cause tracheal compression; rare",
         "Surgery if compressive; tamoxifen reported helpful"],
        ["Acute Suppurative",
         "Bacterial (Staph/Strep); tender, hot, red; fever; abscess formation; rare",
         "Antibiotics; surgical drainage if abscess"],
        ["Radiation-induced",
         "After 131I therapy; transient thyroiditis; usually mild",
         "Symptomatic; anti-inflammatory"],
    ]
    cw_vals = [3.2*cm, (W-4*cm-3.2*cm-4.5*cm), 4.5*cm]
    t = Table(data, colWidths=cw_vals, repeatRows=1)
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,0), BLUE),
        ("TEXTCOLOR", (0,0), (-1,0), colors.white),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [LGREY, colors.white]),
        ("TOPPADDING", (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING", (0,0), (-1,-1), 5),
        ("BOX", (0,0), (-1,-1), 0.8, BLUE),
        ("INNERGRID", (0,0), (-1,-1), 0.3, colors.grey),
        ("FONTNAME", (0,1), (-1,-1), "Helvetica"),
        ("FONTSIZE", (0,1), (-1,-1), 8.5),
        ("VALIGN", (0,0), (-1,-1), "TOP"),
        ("WORDWRAP", (0,0), (-1,-1), True),
    ]))
    return t

def keloid_vs_hypertrophic():
    data = [
        [Paragraph("<b>Feature</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white)),
         Paragraph("<b>Keloid</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white)),
         Paragraph("<b>Hypertrophic Scar</b>", sty("Normal", fontSize=9, fontName="Helvetica-Bold", textColor=colors.white))],
        ["Extension beyond wound", "Yes (clawlike projections)", "No"],
        ["Spontaneous regression", "No", "Yes (months)"],
        ["Histology", "Thick hyalinised collagen bundles", "Whorled fibroblasts without hyalinisation"],
        ["Incidence", "More in dark skin", "Any skin type"],
        ["Recurrence after excision", "High", "Low"],
        ["Pruritus/Pain", "Common", "Less common"],
    ]
    cw = (W-4*cm)/3
    t = Table(data, colWidths=[cw, cw, cw])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,0), RED),
        ("TEXTCOLOR", (0,0), (-1,0), colors.white),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [LGREY, colors.white]),
        ("TOPPADDING", (0,0), (-1,-1), 4),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING", (0,0), (-1,-1), 6),
        ("BOX", (0,0), (-1,-1), 0.8, RED),
        ("INNERGRID", (0,0), (-1,-1), 0.3, colors.grey),
        ("FONTNAME", (0,1), (-1,-1), "Helvetica"),
        ("FONTSIZE", (0,1), (-1,-1), 9),
    ]))
    return t

# ═══════════════════════════════════════════════════════════════════════════════
# BUILD CONTENT
# ═══════════════════════════════════════════════════════════════════════════════
story = []

# ─── COVER ───────────────────────────────────────────────────────────────────
story.append(sp(3))
story.append(Paragraph("MBBS PHASE 3 PART 2 — PAPER 1", cover_title))
story.append(Paragraph("Surgery — Model Long Answers", cover_sub))
story.append(sp(0.3))
story.append(HRFlowable(width="100%", thickness=2, color=GOLD, spaceAfter=6))
story.append(Paragraph(
    "Reference Sources: Bailey &amp; Love's Short Practice of Surgery (28th ed.) • "
    "Sabiston Textbook of Surgery (21st ed.) • Schwartz's Principles of Surgery (11th ed.) • "
    "Robbins &amp; Kumar Basic Pathology • Cummings Otolaryngology • Andrews' Diseases of the Skin",
    cover_note))
story.append(HRFlowable(width="100%", thickness=1, color=GOLD, spaceAfter=8))
story.append(sp(1))

# ─── TABLE OF CONTENTS ───────────────────────────────────────────────────────
toc_data = [
    [Paragraph("<b>Question</b>", sty("Normal", fontSize=10, fontName="Helvetica-Bold", textColor=colors.white)),
     Paragraph("<b>Topic</b>", sty("Normal", fontSize=10, fontName="Helvetica-Bold", textColor=colors.white)),
     Paragraph("<b>Marks</b>", sty("Normal", fontSize=10, fontName="Helvetica-Bold", textColor=colors.white))],
    ["Q2", "Surgical Anatomy of Thyroid + Types of Thyroiditis & Management", "20"],
    ["Q3a", "Lipoma and its Types", "5"],
    ["Q3b", "Neurofibroma", "5"],
    ["Q3c", "Total Parenteral Nutrition (TPN)", "5"],
    ["Q3d", "Compartment Syndrome", "5"],
    ["Q3e", "Keloid", "5"],
    ["Q4a", "Why Malignancy is Less Common in Small Intestine", "5"],
    ["Q4b", "Why Appendicitis Must Be Managed Earlier in Children & Elderly", "5"],
    ["Q5a", "Lupus Vulgaris", "5"],
    ["Q5b", "Tropical Ulcer", "5"],
    ["Q5c", "Fistula", "5"],
    ["Q5d", "Hidradenitis Suppurativa", "5"],
    ["Q5e", "Zollinger–Ellison Syndrome", "5"],
    ["Q6", "Emergency Management of Burns Victim", "10"],
]
toc_cw = [1.5*cm, W-4*cm-1.5*cm-1.5*cm, 1.5*cm]
toc_t = Table(toc_data, colWidths=toc_cw)
toc_t.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,0), BLUE),
    ("TEXTCOLOR", (0,0), (-1,0), colors.white),
    ("ROWBACKGROUNDS", (0,1), (-1,-1), [LGREY, colors.white]),
    ("TOPPADDING", (0,0), (-1,-1), 4),
    ("BOTTOMPADDING", (0,0), (-1,-1), 4),
    ("LEFTPADDING", (0,0), (-1,-1), 6),
    ("BOX", (0,0), (-1,-1), 0.8, BLUE),
    ("INNERGRID", (0,0), (-1,-1), 0.3, colors.grey),
    ("FONTSIZE", (0,1), (-1,-1), 9),
    ("ALIGN", (2,0), (2,-1), "CENTER"),
]))
story.append(Paragraph("Contents", sty("Heading1", textColor=BLUE)))
story.append(toc_t)
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# Q2 — Thyroid Surgical Anatomy + Thyroiditis (20 marks)
# ══════════════════════════════════════════════════════════════════════════════
story.append(q_header(2, 20,
    "Surgical Anatomy of Thyroid. Types of Thyroiditis and their Management."))
story.append(sp())

story.append(sub_header("PART A: SURGICAL ANATOMY OF THE THYROID GLAND"))
story.append(sp(0.1))

story.append(p(
    "<b>Position and Shape:</b> The thyroid gland is a bilobed, H-shaped endocrine gland located in the "
    "anterior neck, deep to the strap muscles (sternohyoid, sternothyroid, and omohyoid). "
    "It lies at the level of C5–T1 vertebrae and straddles the trachea and larynx. "
    "The two lateral lobes are joined by the isthmus which overlies the 2nd–4th tracheal rings. "
    "A pyramidal lobe ascends from the isthmus in ~50% of individuals, representing a remnant of the "
    "thyroglossal duct."
))
story.append(p(
    "<b>Dimensions and Weight:</b> Each lobe is approximately 5 cm long, 3 cm wide, and 2 cm thick. "
    "The normal gland weighs 25–40 g. The isthmus is ~2 cm wide and 2 cm tall."
))

story.append(sub("1. Capsule and Fascial Relationships"))
story.append(p(
    "The thyroid is enclosed by a true fibrous capsule which sends septa into the parenchyma. "
    "External to this is the pretracheal fascia (false capsule/surgical capsule), a condensation "
    "of which forms <b>Berry's ligament</b> — a dense band binding the posteromedial lobe to "
    "the trachea and cricoid cartilage. This ligament is surgically important as it is the point "
    "of greatest risk to the <b>recurrent laryngeal nerve (RLN)</b>. The subcapsular plane "
    "(between true and false capsule) is the correct surgical dissection plane."
))

story.append(sub("2. Blood Supply"))
story.append(p("<b>Arterial supply (4 arteries):</b>"))
story.append(bullet("<b>Superior thyroid artery</b> — first branch of the external carotid artery; "
                    "enters the upper pole of each lobe; accompanied by the external branch of the "
                    "superior laryngeal nerve (EBSLN) which must be identified and preserved."))
story.append(bullet("<b>Inferior thyroid artery</b> — from the thyrocervical trunk (subclavian artery); "
                    "enters the lower pole; intimately related to the RLN. "
                    "The relationship is variable: nerve may pass anterior or posterior to the artery."))
story.append(bullet("<b>Thyroidea ima artery</b> — inconstant; arises from the aorta or innominate artery; "
                    "enters the isthmus inferiorly (present in ~3% of individuals)."))
story.append(sp(0.1))
story.append(p("<b>Venous drainage (3 veins per side):</b>"))
story.append(bullet("<b>Superior thyroid vein</b> → drains to internal jugular vein"))
story.append(bullet("<b>Middle thyroid vein</b> → drains to internal jugular vein (no accompanying artery; "
                    "first structure ligated during thyroidectomy)"))
story.append(bullet("<b>Inferior thyroid veins</b> → drain into left brachiocephalic vein (may be bilateral)"))

story.append(sub("3. Nerve Relations — Critical for Surgery"))
story.append(p("<b>Recurrent Laryngeal Nerve (RLN):</b>"))
story.append(bullet("Branch of vagus nerve"))
story.append(bullet("Right RLN loops under the subclavian artery; Left loops under the aortic arch "
                    "(longer course, more susceptible to injury in mediastinal pathology)"))
story.append(bullet("Runs in the tracheo-oesophageal groove then passes deep to Berry's ligament"))
story.append(bullet("Found at the <b>Tubercle of Zuckerkandl</b> — a posterolateral projection "
                    "of the thyroid lobe; the RLN lies medial to it"))
story.append(bullet("Injury causes hoarseness (unilateral) or respiratory distress (bilateral)"))
story.append(sp(0.1))
story.append(p("<b>External Branch of the Superior Laryngeal Nerve (EBSLN):</b>"))
story.append(bullet("Runs adjacent to the superior thyroid pedicle; innervates the cricothyroid muscle"))
story.append(bullet("Injury causes loss of high-pitched phonation ('voice of the surgeon's nightmare')"))

story.append(sub("4. Parathyroid Glands"))
story.append(p(
    "Four parathyroid glands (superior and inferior pairs) lie adjacent to or within the posterior "
    "capsule of the thyroid. <b>Superior parathyroids</b> are more constant (at the level of the "
    "cricothyroid junction). <b>Inferior parathyroids</b> are more variable — may be as low as "
    "the mediastinum. Blood supply is via the inferior thyroid artery. "
    "Careful preservation is essential to avoid post-operative hypocalcaemia."
))

story.append(sub("5. Lymphatic Drainage"))
story.append(p(
    "Lymphatics drain to: <b>prelaryngeal</b> (Delphian node), <b>pretracheal</b>, "
    "<b>paratracheal</b>, and <b>deep cervical</b> nodes. "
    "Lateral spread to jugulodigastric and posterior triangle nodes also occurs. "
    "This pathway is relevant in thyroid cancer staging and node dissection."
))

story.append(sub("6. Embryology (Surgical Relevance)"))
story.append(bullet("Develops from the floor of the pharynx at the foramen caecum (base of tongue) "
                    "at 24 days"))
story.append(bullet("Descends via the thyroglossal duct to its final position"))
story.append(bullet("Incomplete descent → lingual thyroid (most common ectopic site); "
                    "incomplete obliteration → thyroglossal cyst"))
story.append(bullet("C cells originate from neural crest via the ultimobranchial bodies"))

story.append(sp(0.3))
story.append(sub_header("PART B: TYPES OF THYROIDITIS AND MANAGEMENT"))
story.append(sp(0.1))
story.append(p(
    "Thyroiditis refers to inflammation of the thyroid gland. The common feature is disruption of "
    "thyroid follicles → release of preformed T3/T4 → <b>transient thyrotoxicosis</b>, followed "
    "potentially by <b>transient hypothyroidism</b> as stores are depleted. "
    "Permanent hypothyroidism occurs in Hashimoto's thyroiditis."
))
story.append(sp(0.1))
story.append(thyroiditis_table())
story.append(sp(0.1))
story.append(p(
    I("References: Bailey &amp; Love 28th ed., Chapter 55; Robbins &amp; Kumar Basic Pathology; "
      "Cummings Otolaryngology Head and Neck Surgery")
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# Q3 — SHORT NOTES (25 marks)
# ══════════════════════════════════════════════════════════════════════════════
story.append(q_header(3, 25,
    "Short Notes (5 marks each): Lipoma | Neurofibroma | TPN | Compartment Syndrome | Keloid"))
story.append(sp())

# Q3a — Lipoma
story.append(sub_header("Q3a) LIPOMA AND ITS TYPES"))
story.append(p(
    "<b>Definition:</b> A lipoma is the most common soft tissue tumour, composed of mature "
    "adipocytes. It is benign, slow-growing, and encapsulated. Occurs in any fatty tissue."
))
story.append(p("<b>Macroscopy:</b> Soft, lobulated, yellowish mass; slips between examining fingers "
               "(slip sign). Encapsulated with thin fibrous capsule."))
story.append(p("<b>Microscopy:</b> Mature adipocytes indistinguishable from normal fat, arranged in lobules "
               "separated by fibrous septa."))
story.append(sub("Types of Lipoma"))
story.append(bullet("<b>Simple/Superficial Lipoma:</b> Most common; subcutaneous, soft, fluctuant "
                    "(pseudofluctuance), transilluminable, non-tender, mobile"))
story.append(bullet("<b>Deep lipoma:</b> Subfascial, submuscular, subsynovial — harder to diagnose "
                    "clinically; requires MRI"))
story.append(bullet("<b>Angiolipoma:</b> Contains blood vessels; tender; usually forearm; "
                    "multiple and painful"))
story.append(bullet("<b>Fibrolipoma:</b> Abundant fibrous tissue; firmer consistency"))
story.append(bullet("<b>Myxolipoma:</b> Contains mucoid degeneration areas"))
story.append(bullet("<b>Myelolipoma:</b> Contains haematopoietic tissue; found in adrenal gland"))
story.append(bullet("<b>Hibernoma:</b> Brown fat tumour; interscapular region; more vascular"))
story.append(bullet("<b>Pleomorphic lipoma/Spindle cell lipoma:</b> Seen in elderly men; "
                    "back/shoulder; contains atypical giant cells — benign"))
story.append(bullet("<b>Diffuse lipomatosis:</b> Unencapsulated fat proliferation in a body region "
                    "(Madelung's disease — symmetric cervical lipomatosis)"))
story.append(bullet("<b>Lipoma arborescens:</b> Villous frond-like synovial lipoma; usually knee"))
story.append(p(
    "<b>Malignant counterpart:</b> Liposarcoma. Suspect if: rapidly enlarging, size >5 cm, "
    "deep to fascia, hard/fixed. Biopsy mandatory before excision."
))
story.append(p("<b>Treatment:</b> Surgical excision with intact capsule through appropriate incision. "
               "Liposuction for cosmesis in selected cases."))
story.append(sp())

# Q3b — Neurofibroma
story.append(sub_header("Q3b) NEUROFIBROMA"))
story.append(p(
    "<b>Definition:</b> A benign peripheral nerve sheath tumour arising from Schwann cells, "
    "fibroblasts, and perineural cells of peripheral nerves. May occur sporadically or in association "
    "with <b>Neurofibromatosis type 1 (NF-1, von Recklinghausen's disease)</b>."
))
story.append(p("<b>Pathology:</b> Unencapsulated tumour with spindle-shaped cells embedded in "
               "myxoid stroma with collagen. S-100 protein positive on immunohistochemistry."))
story.append(sub("Types"))
story.append(bullet("<b>Localized (cutaneous) neurofibroma:</b> Most common; solitary; "
                    "soft, flesh-coloured skin nodule; buttonhole sign (invaginates on pressure)"))
story.append(bullet("<b>Plexiform neurofibroma:</b> Multiple nerve fascicles involved; "
                    "produces 'bag of worms' feel; <b>pathognomonic of NF-1</b>; "
                    "higher risk of malignant transformation"))
story.append(bullet("<b>Diffuse neurofibroma:</b> Infiltrates dermis and subcutis; "
                    "plaquelike thickening; usually head/neck in young patients"))
story.append(sub("Neurofibromatosis Type 1 (NF-1)"))
story.append(p(
    "Autosomal dominant; chromosome 17q11.2 mutation; NF1 gene encodes neurofibromin (tumour suppressor). "
    "Diagnosis: <b>2 or more</b> of the following (NIH criteria):"
))
story.append(bullet("≥6 café-au-lait macules (>5 mm prepubertal; >15 mm postpubertal)"))
story.append(bullet("≥2 neurofibromas or ≥1 plexiform neurofibroma"))
story.append(bullet("Axillary/inguinal freckling (Crowe's sign)"))
story.append(bullet("Optic glioma"))
story.append(bullet("≥2 Lisch nodules (iris hamartomas)"))
story.append(bullet("Distinctive osseous lesion (sphenoid wing dysplasia)"))
story.append(bullet("First-degree relative with NF-1"))
story.append(p(
    "<b>Complications:</b> Malignant peripheral nerve sheath tumour (MPNST) in 2–5%; "
    "scoliosis, learning disability, hypertension (from renovascular disease or "
    "phaeochromocytoma), epilepsy."
))
story.append(p("<b>Treatment:</b> Surgical excision for symptomatic or suspicious lesions. "
               "Selumetinib (MEK inhibitor) approved for inoperable plexiform neurofibromas in NF-1."))
story.append(sp())

# Q3c — TPN
story.append(sub_header("Q3c) TOTAL PARENTERAL NUTRITION (TPN)"))
story.append(p(
    "<b>Definition:</b> Provision of all nutritional requirements (calories, protein, fat, "
    "electrolytes, vitamins, trace elements, water) via the intravenous route, bypassing the GI tract."
))
story.append(p("<b>Indications (when gut cannot be used):</b>"))
story.append(bullet("Short bowel syndrome"))
story.append(bullet("High-output intestinal fistulae"))
story.append(bullet("Prolonged ileus / intestinal obstruction"))
story.append(bullet("Severe pancreatitis with enteral feeding intolerance"))
story.append(bullet("Inflammatory bowel disease (severe Crohn's with failure to thrive)"))
story.append(bullet("Post-major GI surgery when enteral feeding not possible >5–7 days"))
story.append(bullet("Mesenteric ischaemia; intestinal pseudo-obstruction"))
story.append(sub("Components of TPN Solution"))
story.append(bullet("<b>Carbohydrate:</b> Glucose (50–60% of non-protein calories); 3.4 kcal/g; "
                    "max 4–5 mg/kg/min to avoid hyperglycaemia"))
story.append(bullet("<b>Lipid emulsion:</b> 20–40% of total calories; "
                    "soya/olive/fish oil-based; provides essential fatty acids"))
story.append(bullet("<b>Amino acids:</b> 1–1.5 g/kg/day; provides nitrogen for protein synthesis"))
story.append(bullet("<b>Electrolytes:</b> Na+, K+, Mg2+, Ca2+, PO4 3− — tailored daily"))
story.append(bullet("<b>Vitamins:</b> Fat-soluble (A, D, E, K) and water-soluble (B-complex, C)"))
story.append(bullet("<b>Trace elements:</b> Zn, Cu, Mn, Se, Cr, Mo"))
story.append(bullet("<b>Water:</b> ~30–35 mL/kg/day"))
story.append(sub("Monitoring"))
story.append(bullet("Daily: Blood glucose, U&amp;E, fluid balance, line site"))
story.append(bullet("Twice weekly: LFTs, magnesium, phosphate"))
story.append(bullet("Weekly: Triglycerides, trace elements, vitamin levels"))
story.append(sub("Complications"))
story.append(p("<b>Line-related:</b> Pneumothorax, arterial injury, air embolism, line sepsis "
               "(Staphylococcus epidermidis most common), thrombosis"))
story.append(p("<b>Metabolic:</b>"))
story.append(bullet("Hyperglycaemia → insulin therapy required"))
story.append(bullet("Refeeding syndrome → hypophosphataemia, hypokalaemia, hypomagnesaemia "
                    "(risk if malnourished patient refed rapidly)"))
story.append(bullet("Hepatic steatosis/IFALD (Intestinal Failure Associated Liver Disease)"))
story.append(bullet("Essential fatty acid deficiency if fat-free TPN prolonged"))
story.append(p("<b>Route:</b> Central venous access mandatory (high osmolarity ~1800 mOsm/L). "
               "Common sites: subclavian, internal jugular, PICC line."))
story.append(sp())

# Q3d — Compartment Syndrome
story.append(sub_header("Q3d) COMPARTMENT SYNDROME"))
story.append(p(
    "<b>Definition:</b> A condition in which increased pressure within a closed fascial compartment "
    "compromises tissue perfusion, leading to ischaemia and necrosis if untreated. "
    "Defined as compartment pressure >30 mmHg OR within 30 mmHg of diastolic blood pressure "
    "(delta P = diastolic BP - compartment pressure &lt;30 mmHg)."
))
story.append(sub("Aetiology / Causes"))
story.append(bullet("<b>Fractures:</b> Tibial shaft fracture (most common), forearm fractures"))
story.append(bullet("Crush injuries, high energy trauma"))
story.append(bullet("Reperfusion after vascular injury/ischaemia"))
story.append(bullet("Burns — circumferential full-thickness burns"))
story.append(bullet("Constrictive casts, tight wound dressings"))
story.append(bullet("Bleeding diathesis, anticoagulation"))
story.append(bullet("Snakebite envenomation, IV drug use extravasation"))
story.append(sub("Pathophysiology"))
story.append(p(
    "Raised compartment pressure → venous outflow obstruction → further oedema → "
    "pressure exceeds capillary perfusion pressure → arterial inflow diminished → "
    "ischaemia → cell necrosis → rhabdomyolysis → myoglobinuria → renal failure."
))
story.append(sub("Clinical Features — 6 Ps"))
for itm in ["<b>Pain</b> — disproportionate to injury; pain on passive stretch (earliest and most reliable sign)",
            "<b>Pressure</b> — tense, woody compartment on palpation",
            "<b>Paraesthesia</b> — tingling/numbness in distribution of nerve within compartment",
            "<b>Paralysis</b> — weakness/inability to move affected muscles (late sign)",
            "<b>Pallor</b> — pale skin",
            "<b>Pulselessness</b> — very late sign; presence of pulse does NOT exclude compartment syndrome"]:
    story.append(bullet(itm))
story.append(sub("Diagnosis"))
story.append(bullet("Clinical diagnosis primarily"))
story.append(bullet("Compartment pressure measurement: Stryker device or modified arterial line"))
story.append(bullet("Delta P = Diastolic BP − Compartment Pressure; if &lt;30 mmHg → fasciotomy"))
story.append(sub("Management"))
story.append(p("<b>Emergency fasciotomy</b> — definitive treatment; must not be delayed."))
story.append(bullet("Lower leg: 2-incision 4-compartment fasciotomy (medial + lateral incisions)"))
story.append(bullet("Forearm: Volar + dorsal fasciotomy"))
story.append(bullet("Thigh: Single lateral incision"))
story.append(bullet("Hand/foot: Multiple dorsal incisions"))
story.append(p("Post-fasciotomy: wound left open, dressed with negative pressure wound therapy "
               "(NPWT) or wet dressings; closed at 48–72 hours or split-skin grafting as needed."))
story.append(p("<b>Secondary management:</b> Monitor renal function (myoglobinuria); "
               "IV fluids to maintain urine output >1 mL/kg/h; alkalinise urine if needed; "
               "monitor electrolytes (hyperkalaemia from cell lysis)."))
story.append(sp())

# Q3e — Keloid
story.append(sub_header("Q3e) KELOID"))
story.append(p(
    "<b>Definition:</b> A keloid is an exuberant, firm, fibrous scar that extends beyond the margins "
    "of the original wound (distinguishing it from a hypertrophic scar). "
    "It represents a pathological response to wound healing with excessive deposition of collagen."
))
story.append(p(
    "<b>Epidemiology:</b> More common in dark-skinned individuals (African, Asian populations); "
    "15–20 times more common in black persons. Peak incidence: 10–30 years."
))
story.append(sub("Aetiology"))
story.append(bullet("Trauma: incisions, lacerations, burns, acne, ear piercing, tattooing, vaccinations"))
story.append(bullet("Genetic predisposition: higher concordance in monozygotic twins"))
story.append(bullet("Sites of predilection: sternum, shoulders, upper back, earlobes, neck"))
story.append(sub("Pathology"))
story.append(p(
    "Microscopically: <b>thick, hyalinised collagen bundles</b> (distinguishing feature from "
    "hypertrophic scar) arranged in whorls; myofibroblasts; increased mucopolysaccharides; "
    "numerous mast cells. Epidermis thinned due to pressure."
))
story.append(keloid_vs_hypertrophic())
story.append(sp(0.1))
story.append(sub("Treatment"))
story.append(bullet("<b>Intralesional corticosteroid injection</b> (triamcinolone 10–40 mg/mL): "
                    "first-line; injections every 6–8 weeks; causes softening and itch relief"))
story.append(bullet("<b>Pressure therapy:</b> Silicone gel sheets, pressure garments — "
                    "worn 23 h/day for ≥6 months; most effective for burn keloids"))
story.append(bullet("<b>Surgical excision:</b> High recurrence (up to 80%) if used alone; "
                    "must be combined with adjuvant therapy"))
story.append(bullet("<b>Radiotherapy:</b> Post-excision superficial radiotherapy reduces recurrence; "
                    "avoid in children"))
story.append(bullet("<b>Laser therapy:</b> Pulsed dye laser (595 nm) reduces vascularity and redness"))
story.append(bullet("<b>Intralesional 5-FU/bleomycin:</b> Used in combination with steroids "
                    "for resistant keloids"))
story.append(bullet("<b>Cryotherapy:</b> Useful for small lesions"))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# Q4 — EXPLAIN WHY (10 marks)
# ══════════════════════════════════════════════════════════════════════════════
story.append(q_header(4, 10,
    "Explain Why: a) Malignancy Rare in Small Intestine  b) Appendicitis: Earlier Management"))
story.append(sp())

story.append(sub_header("Q4a) WHY IS MALIGNANCY LESS COMMON IN THE SMALL INTESTINE?"))
story.append(p(
    "Despite accounting for 75% of the length and 90% of the mucosal surface area of the "
    "alimentary tract, the small intestine accounts for only <b>1–3% of all GI malignancies</b>. "
    "This paradox is explained by several protective mechanisms:"
))
story.append(p("<b>1. Rapid Transit Time:</b>"))
story.append(p(
    "Small intestinal contents are in liquid form and transit is rapid (2–6 hours), "
    "minimising contact time of potential carcinogens (bile acids, food-derived mutagens) "
    "with the mucosa. In contrast, colonic transit takes 24–72 hours."
))
story.append(p("<b>2. Liquid Luminal Content:</b>"))
story.append(p(
    "The liquid consistency reduces mechanical mucosal trauma and abrasion compared to "
    "the formed stool in the colon. This minimises DNA damage from physical irritation."
))
story.append(p("<b>3. High Immunological Activity (Gut-Associated Lymphoid Tissue — GALT):</b>"))
story.append(p(
    "Peyer's patches in the ileum contain abundant lymphoid tissue with macrophages, "
    "IgA-secreting plasma cells, and T-lymphocytes. High IgA concentrations neutralise "
    "carcinogens and antigens before mucosal contact. This immunosurveillance rapidly "
    "eliminates transformed cells."
))
story.append(p("<b>4. Alkaline pH:</b>"))
story.append(p(
    "The small intestinal pH is alkaline (6.5–7.5) compared to the acidic faecal content "
    "of the colon. Bile acids are less cytotoxic and carcinogenic at alkaline pH. "
    "Secondary bile acids (deoxycholate, lithocholate — known carcinogens) are formed "
    "by bacterial action, which is minimal in the small bowel."
))
story.append(p("<b>5. Low Bacterial Count:</b>"))
story.append(p(
    "The small bowel has a relatively sparse bacterial flora (10^3–10^4 organisms/mL) "
    "due to rapid transit and high IgA. The colon has 10^11 organisms/mL. "
    "Bacteria in the colon generate carcinogenic metabolites from bile acids and "
    "dietary substances (heterocyclic amines, N-nitroso compounds)."
))
story.append(p("<b>6. Rapid Epithelial Turnover:</b>"))
story.append(p(
    "Small intestinal enterocytes have a very high turnover rate (3–5 days), "
    "meaning any cell accumulating mutations is rapidly shed before transformation. "
    "Apoptotic mechanisms are highly active."
))
story.append(p("<b>7. High Local Levels of Benzpyrene Hydroxylase:</b>"))
story.append(p(
    "This enzyme detoxifies polycyclic aromatic hydrocarbons (a class of carcinogens) "
    "within the small bowel mucosa."
))
story.append(p(
    "<b>Conclusion:</b> The combination of rapid transit, alkaline milieu, low bacterial load, "
    "robust immunological surveillance, high epithelial turnover, and detoxifying enzymes "
    "collectively make the small intestine remarkably resistant to carcinogenesis."
))
story.append(sp())

story.append(sub_header("Q4b) WHY MUST APPENDICITIS BE MANAGED EARLIER IN CHILDREN AND ELDERLY?"))
story.append(p(
    "Acute appendicitis can progress to perforation, peritonitis, and sepsis rapidly. "
    "However, in the <b>paediatric</b> and <b>elderly</b> populations, this progression "
    "is accelerated and the consequences are more severe, necessitating earlier intervention:"
))
story.append(sub("In CHILDREN (especially under 5 years)"))
story.append(p("<b>1. Underdeveloped/thin-walled appendix:</b> The appendix wall is thinner "
               "and less able to withstand pressure — perforation occurs within 24–36 hours "
               "of symptom onset (vs. 48–72 hours in adults)."))
story.append(p("<b>2. Immature omentum:</b> The greater omentum is small and underdeveloped "
               "in young children and cannot 'wall off' or localise a perforated appendix. "
               "This leads to <b>generalised peritonitis</b> rather than a localised appendix abscess."))
story.append(p("<b>3. Poor history and diagnostic difficulty:</b> Young children cannot localise "
               "pain accurately. Clinical features are often atypical (diffuse abdominal pain, "
               "vomiting, diarrhoea), causing diagnostic delay and late presentation."))
story.append(p("<b>4. Rapid dehydration and sepsis:</b> Children have higher surface area to "
               "volume ratio; fluid losses and electrolyte imbalance occur faster; septic shock "
               "can develop quickly."))
story.append(p("<b>5. Rapidly progressing inflammatory response:</b> Higher metabolic rate "
               "accelerates the inflammatory cascade."))
story.append(sub("In ELDERLY (over 60 years)"))
story.append(p("<b>1. Impaired immune response:</b> Immunosenescence means the inflammatory "
               "response is blunted; classical signs (fever, leukocytosis, rebound tenderness) "
               "may be absent or minimal, causing late diagnosis."))
story.append(p("<b>2. Atypical presentation:</b> Pain may be mild or diffuse; temperature may "
               "be normal or mildly elevated; leukocytosis may be absent (20% of elderly "
               "perforations have normal WBC)."))
story.append(p("<b>3. Higher perforation rate:</b> 70% of elderly patients present with perforated "
               "appendicitis (vs. 20–30% in younger adults) due to diagnostic delay."))
story.append(p("<b>4. Co-morbidities:</b> Hypertension, diabetes, COPD, cardiac disease, "
               "anticoagulant use — all increase surgical risk and complications. "
               "Early surgery when patient is better physiologically conditioned is safer."))
story.append(p("<b>5. Thickened, fibrotic appendiceal wall:</b> Paradoxically, although the "
               "wall is thicker (from previous inflammation), blood supply may be atheromatous "
               "and reduced, predisposing to earlier ischaemic perforation."))
story.append(p("<b>6. Higher mortality from perforation:</b> Mortality from perforated appendicitis "
               "is up to 15% in the elderly vs. &lt;1% in young adults. Earlier appendicectomy "
               "prevents this fatal complication."))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# Q5 — SHORT NOTES (25 marks)
# ══════════════════════════════════════════════════════════════════════════════
story.append(q_header(5, 25,
    "Short Notes: Lupus Vulgaris | Tropical Ulcer | Fistula | Hidradenitis Suppurativa | Zollinger–Ellison"))
story.append(sp())

# Q5a — Lupus Vulgaris
story.append(sub_header("Q5a) LUPUS VULGARIS"))
story.append(p(
    "<b>Definition:</b> Lupus vulgaris is the most common and severe form of cutaneous tuberculosis, "
    "caused by <i>Mycobacterium tuberculosis</i>. It is a chronic, progressive, destructive form of "
    "skin TB that can lead to permanent disfigurement."
))
story.append(p(
    "<b>Pathogenesis:</b> Usually represents reactivation or haematogenous/lymphatic seeding "
    "in a previously sensitised individual. Also may arise from direct inoculation or contiguous spread. "
    "Tuberculin test strongly positive (high sensitisation)."
))
story.append(sub("Clinical Features"))
story.append(bullet("Sites: Head and neck (commonest — especially nose and cheek), "
                    "buttocks, extremities"))
story.append(bullet("Primary lesion: Apple-jelly nodule (lupoma) — reddish-brown, "
                    "translucent papule/nodule showing characteristic <b>apple-jelly colour</b> "
                    "on diascopy (glass slide pressure)"))
story.append(bullet("Lesions coalesce into plaques with irregular borders; central scarring "
                    "with active advancing edge"))
story.append(bullet("Ulceration and crusting in long-standing cases"))
story.append(bullet("Mutilating destruction of nose (lupus nasi), ears, lips"))
story.append(bullet("Squamous cell carcinoma can develop in longstanding lupus vulgaris scars (Marjolin's ulcer)"))
story.append(sub("Investigations"))
story.append(bullet("Skin biopsy: Epithelioid cell granulomas with Langhans giant cells; "
                    "central caseation uncommon"))
story.append(bullet("AFB smear/culture from lesion"))
story.append(bullet("Tuberculin test (Mantoux) — strongly positive"))
story.append(bullet("Chest X-ray (active/previous TB)"))
story.append(bullet("QuantiFERON-TB Gold or ELISPOT"))
story.append(sub("Management"))
story.append(p("<b>Anti-tuberculosis therapy</b> as per standard 6-month regimen:"))
story.append(bullet("Intensive phase (2 months): Isoniazid + Rifampicin + Pyrazinamide + Ethambutol (2HRZE)"))
story.append(bullet("Continuation phase (4 months): Isoniazid + Rifampicin (4HR)"))
story.append(bullet("Reconstructive surgery for deformity after completion of treatment"))
story.append(sp())

# Q5b — Tropical Ulcer
story.append(sub_header("Q5b) TROPICAL ULCER"))
story.append(p(
    "<b>Definition:</b> Tropical ulcer (also known as Aden ulcer, jungle rot, or Naga sore) is "
    "an acute, rapidly developing, painless-to-painful cutaneous ulcer occurring in tropical regions, "
    "primarily affecting the lower limbs. Primarily seen in malnourished individuals in sub-Saharan Africa, "
    "South Asia, and Pacific islands."
))
story.append(p(
    "<b>Aetiology:</b> Polymicrobial — classically associated with <i>Fusobacterium ulcerans</i> "
    "and <i>Treponema vincenti</i> (previously Borrelia vincenti). Minor trauma is the precipitating factor. "
    "Malnutrition, poor hygiene, and immunosuppression are predisposing factors."
))
story.append(sub("Clinical Features"))
story.append(bullet("Site: Lower third of leg, especially around the ankle"))
story.append(bullet("Onset: Papule or pustule after minor trauma → rapidly ulcerates within days"))
story.append(bullet("Ulcer characteristics: Punched-out, circular; foul-smelling, undermined edges; "
                    "grey-brown necrotic slough base; surrounding erythema and oedema"))
story.append(bullet("Acute phase: Painful, rapid expansion, systemic upset"))
story.append(bullet("Chronic phase: Less painful; fibrous, indurated edges; may reach 10–15 cm"))
story.append(bullet("Complications: Secondary infection, osteomyelitis, squamous cell carcinoma "
                    "(Marjolin's ulcer) in long-standing lesions (10–25 year latency)"))
story.append(sub("Investigations"))
story.append(bullet("Swab culture; dark-ground microscopy for spirochaetes"))
story.append(bullet("Biopsy to exclude malignant transformation"))
story.append(bullet("X-ray if osteomyelitis suspected"))
story.append(sub("Management"))
story.append(bullet("Nutritional support: High protein diet, vitamins"))
story.append(bullet("Wound care: Saline wash, debridement, daily dressings"))
story.append(bullet("Antibiotics: Penicillin (crystalline) + Metronidazole for acute phase; "
                    "Amoxicillin for oral maintenance"))
story.append(bullet("Skin grafting: Split-thickness skin graft (STSG) for large ulcers after "
                    "achieving clean bed"))
story.append(bullet("Surgery for malignant transformation"))
story.append(sp())

# Q5c — Fistula
story.append(sub_header("Q5c) FISTULA"))
story.append(p(
    "<b>Definition:</b> A fistula is an <b>abnormal communication between two epithelium-lined "
    "surfaces</b>. The tract is usually lined by granulation tissue, which may become epithelialised "
    "in chronic cases. Fistulae are either congenital or acquired."
))
story.append(sub("Classification"))
story.append(p("<b>By aetiology:</b>"))
story.append(bullet("<b>Congenital:</b> Tracheo-oesophageal fistula, branchial fistula, "
                    "thyroglossal fistula, vesicouterine fistula"))
story.append(bullet("<b>Acquired:</b> Inflammatory (Crohn's disease, diverticulitis), post-surgical, "
                    "malignant, traumatic, radiation-induced, infective (actinomycosis)"))
story.append(p("<b>By anatomy:</b>"))
story.append(bullet("<b>External (cutaneous) fistula:</b> Opens onto skin surface — "
                    "e.g. enterocutaneous fistula, orocutaneous"))
story.append(bullet("<b>Internal fistula:</b> Between two hollow organs — "
                    "e.g. colovesical (faecaluria, pneumaturia), colovaginal, biliary-enteric"))
story.append(p("<b>By output (enterocutaneous fistulae):</b>"))
story.append(bullet("Low output: &lt;200 mL/24h — usually colonic; easier to manage"))
story.append(bullet("Moderate output: 200–500 mL/24h"))
story.append(bullet("High output: &gt;500 mL/24h — usually small bowel; metabolic consequences severe"))
story.append(sub("Conditions Preventing Spontaneous Closure (FRIENDS)"))
story.append(p(
    "<b>F</b>oreign body in tract | <b>R</b>adiation damage | <b>I</b>nflammation/Infection | "
    "<b>E</b>pithelialization of tract | <b>N</b>eoplasm | <b>D</b>istal obstruction | "
    "<b>S</b>hort tract (&lt;2 cm) / <b>S</b>teroids"
))
story.append(sub("Management Principles"))
story.append(bullet("<b>Resuscitation:</b> Correct fluid/electrolyte deficit — especially in "
                    "high-output small bowel fistulae"))
story.append(bullet("<b>Nutrition:</b> TPN often required; reduce GI secretions"))
story.append(bullet("<b>Sepsis control:</b> Drain collections; antibiotics as needed"))
story.append(bullet("<b>Skin protection:</b> Stoma appliances, barrier creams for effluent protection"))
story.append(bullet("<b>Conservative:</b> 30–40% close spontaneously if no 'FRIENDS' factors, "
                    "usually within 4–6 weeks"))
story.append(bullet("<b>Surgical:</b> Resection + primary anastomosis; bypass; diversion stoma"))
story.append(bullet("<b>Somatostatin analogues</b> (octreotide) reduce fistula output in "
                    "selected cases"))
story.append(sp())

# Q5d — Hidradenitis Suppurativa
story.append(sub_header("Q5d) HIDRADENITIS SUPPURATIVA (HS)"))
story.append(p(
    "<b>Definition:</b> Hidradenitis suppurativa is a chronic, recurrent, debilitating inflammatory "
    "skin disease of the apocrine gland-bearing skin, characterised by painful nodules, abscesses, "
    "sinus tracts, and scarring."
))
story.append(p(
    "<b>Pathogenesis:</b> Primarily a disease of follicular occlusion (not a primary apocrine "
    "gland disorder as once thought). Follicular hyperkeratosis → occlusion of hair follicle → "
    "bacterial superinfection (Staph. aureus, Streptococcus) → rupture → intense inflammatory response → "
    "abscess → chronic sinus tract formation → scarring."
))
story.append(p(
    "<b>Risk factors:</b> Obesity, smoking, diabetes, family history (30–40% have first-degree "
    "relative), hormonal factors (worse perimenstrually)."
))
story.append(sub("Sites"))
story.append(bullet("Axillae (most common), groins, perineum, buttocks, inframammary region, "
                    "inner thighs"))
story.append(sub("Hurley Staging"))
story.append(bullet("<b>Stage I:</b> Abscess formation, single or multiple, without sinus tracts "
                    "or cicatrization"))
story.append(bullet("<b>Stage II:</b> Recurrent abscesses with tract formation and scarring; "
                    "single or multiple widely separated lesions"))
story.append(bullet("<b>Stage III:</b> Diffuse or near-diffuse involvement; multiple interconnected "
                    "tracts and abscesses; entire area affected"))
story.append(sub("Management"))
story.append(p("<b>Medical:</b>"))
story.append(bullet("Antibiotics: Topical clindamycin; systemic tetracyclines (doxycycline), "
                    "clindamycin + rifampicin combination"))
story.append(bullet("Anti-androgens: Combined OCP, spironolactone (in women)"))
story.append(bullet("Biologics: <b>Adalimumab</b> (anti-TNF-α) — only FDA-approved biologic for HS; "
                    "Secukinumab (IL-17A inhibitor) recently approved"))
story.append(bullet("Intralesional steroids: For acute flares"))
story.append(p("<b>Surgical:</b>"))
story.append(bullet("Incision and drainage: For acute painful abscesses (relieves pain but does "
                    "not prevent recurrence)"))
story.append(bullet("Deroofing/unroofing: Excision of roof of sinus tracts; low recurrence"))
story.append(bullet("Wide local excision: Definitive treatment for Stage III; extends to healthy "
                    "tissue; wound left to heal by secondary intention or STSG"))
story.append(sp())

# Q5e — Zollinger-Ellison Syndrome
story.append(sub_header("Q5e) ZOLLINGER–ELLISON SYNDROME (ZES)"))
story.append(p(
    "<b>Definition:</b> Zollinger–Ellison syndrome is a condition characterised by gastric acid "
    "hypersecretion due to a gastrin-secreting tumour (<b>gastrinoma</b>), causing recurrent "
    "severe peptic ulcers, diarrhoea, and oesophagitis. Described by Zollinger and Ellison in 1955."
))
story.append(p(
    "<b>Epidemiology:</b> Rare (1–3 per million/year). Most cases sporadic; ~25% associated with "
    "<b>MEN-1</b> (multiple endocrine neoplasia type 1 — parathyroid, pituitary, pancreatic tumours)."
))
story.append(sub("Gastrinoma Triangle"))
story.append(p(
    "~90% of gastrinomas are located within the <b>gastrinoma triangle</b>:"
))
story.append(bullet("Superior border: Junction of cystic duct and common bile duct"))
story.append(bullet("Inferior border: Junction of 2nd and 3rd parts of duodenum"))
story.append(bullet("Medial border: Junction of head and neck of pancreas"))
story.append(p(
    "Within the triangle: <b>Duodenum</b> (45–60% of tumours) > Pancreatic head > "
    "Lymph nodes. Most are malignant (60%) with lymph node metastases."
))
story.append(sub("Clinical Features"))
story.append(bullet("Peptic ulcer disease — severe, recurrent, often multiple, "
                    "atypical locations (post-bulbar, jejunum)"))
story.append(bullet("Diarrhoea (50–60%) — from acid inactivating pancreatic enzymes and "
                    "damaging small bowel mucosa; resolves with acid suppression"))
story.append(bullet("Oesophagitis — from massive acid reflux"))
story.append(bullet("Abdominal pain — prominent and severe"))
story.append(bullet("Hypertrophic gastric folds on endoscopy"))
story.append(sub("Investigations"))
story.append(bullet("<b>Fasting serum gastrin</b> (&gt;1000 pg/mL with gastric pH &lt;2 — diagnostic)"))
story.append(bullet("<b>Basal acid output (BAO)</b>: >15 mEq/h (or >5 in post-gastrectomy patients)"))
story.append(bullet("<b>Secretin stimulation test:</b> IV secretin → paradoxical rise in gastrin "
                    "(&gt;200 pg/mL increase) — most sensitive provocative test"))
story.append(bullet("Imaging: CT/MRI, endoscopic ultrasound (EUS — most sensitive), "
                    "68Ga-DOTATATE PET-CT (somatostatin receptor scintigraphy)"))
story.append(sub("Management"))
story.append(p("<b>Medical:</b>"))
story.append(bullet("High-dose <b>Proton Pump Inhibitors</b> (PPIs): Omeprazole 40–120 mg/day; "
                    "controls acid hypersecretion; first-line"))
story.append(bullet("Somatostatin analogues (octreotide): Reduces gastrin secretion; "
                    "used for metastatic disease"))
story.append(p("<b>Surgical:</b>"))
story.append(bullet("Curative resection if tumour localised and no MEN-1"))
story.append(bullet("In MEN-1: Surgery deferred unless tumour >2 cm (MEN-1 gastrinomas are "
                    "multiple and diffuse)"))
story.append(bullet("Liver metastases: Resection, ablation, hepatic artery embolisation"))
story.append(p("<b>Prognosis:</b> 5-year survival ~65–80% for localised disease; "
               "~30% for disease with liver metastases. MEN-1 associated ZES has better prognosis."))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# Q6 — Emergency Management of Burns (10 marks)
# ══════════════════════════════════════════════════════════════════════════════
story.append(q_header(6, 10,
    "Emergency Management of a Burns Victim"))
story.append(sp())

story.append(p(
    "Burns are a major cause of trauma, morbidity, and mortality worldwide. "
    "Effective emergency management within the 'golden hour' significantly improves outcomes "
    "by preventing systemic complications including shock, inhalation injury, and sepsis. "
    "Management follows the standard <b>ATLS (Advanced Trauma Life Support)</b> principles."
))
story.append(sp(0.1))
story.append(sub_header("STEP-BY-STEP EMERGENCY MANAGEMENT FLOWCHART"))
story.append(sp(0.1))
for fl in flowchart_burns():
    story.append(fl)
story.append(sp(0.2))

story.append(sub("1. Scene Safety and Stopping the Burning Process"))
story.append(bullet("Remove patient from burning source; stop smouldering clothing"))
story.append(bullet("Chemical burns: Brush off dry chemical first; copious water irrigation "
                    "≥20 minutes (do not use antidotes)"))
story.append(bullet("Electrical burns: Isolate power supply before touching patient"))
story.append(bullet("Cool the burn with tepid water (15–25°C) for 20 minutes — reduces depth "
                    "of burn and pain. Do NOT use ice (causes vasoconstriction and worsens injury)."))

story.append(sub("2. Primary Survey (ABCDE)"))
story.append(p("<b>A — Airway (with C-spine control if trauma):</b>"))
story.append(bullet("Signs of airway compromise: Stridor, hoarseness, facial burns, "
                    "singed nasal hair, soot in mouth/nares, blistering in oropharynx"))
story.append(bullet("Early intubation if any inhalation injury suspected "
                    "(oedema develops rapidly — delay makes intubation impossible)"))
story.append(bullet("100% oxygen via non-rebreather mask for all significant burns"))
story.append(p("<b>B — Breathing:</b>"))
story.append(bullet("Assess respiratory rate, oxygen saturation, chest movement"))
story.append(bullet("Circumferential chest burns → escharotomy if respiratory compromise"))
story.append(bullet("CO poisoning: treat with 100% O₂ until COHb &lt;5%; "
                    "consider hyperbaric O₂ if levels >25%"))
story.append(p("<b>C — Circulation:</b>"))
story.append(bullet("Two large-bore IV cannulae (14–16G) through unburned skin if possible"))
story.append(bullet("Begin fluid resuscitation; draw bloods (FBC, U&E, glucose, group+screen, "
                    "lactate, COHb, ABG)"))
story.append(p("<b>D — Disability (Neurological):</b>"))
story.append(bullet("Assess GCS; analgesia (IV morphine 0.1 mg/kg titrated)"))
story.append(p("<b>E — Exposure:</b>"))
story.append(bullet("Full exposure to assess all burns; maintain warmth (hypothermia worsens coagulopathy)"))

story.append(sub("3. Assessment of Burn Severity"))
story.append(p("<b>a) Total Body Surface Area (%TBSA) — Rule of Nines:</b>"))
story.append(rule_of_nines_table())
story.append(sp(0.1))
story.append(p("Palm rule: Patient's palm (fingers closed) = approximately 1% TBSA. "
               "Useful for patchy burns."))
story.append(sp(0.1))
story.append(p("<b>b) Depth Assessment:</b>"))
story.append(bullet("<b>Superficial (1st degree):</b> Epidermis only; erythema, pain, no blistering "
                    "(e.g. sunburn) — not included in TBSA calculation for resuscitation"))
story.append(bullet("<b>Superficial partial-thickness (2nd degree):</b> Epidermis + superficial dermis; "
                    "blistering, moist, extremely painful, pink/red, brisk capillary refill"))
story.append(bullet("<b>Deep partial-thickness (2nd degree):</b> Deep dermis involved; "
                    "reduced/absent pain, white/yellow, delayed capillary refill"))
story.append(bullet("<b>Full-thickness (3rd degree):</b> All dermis destroyed; leathery, pale/brown/black, "
                    "painless, no blistering, does not blanch; requires grafting"))
story.append(bullet("<b>4th degree:</b> Extends to muscle, bone, tendon — electrical burns common cause"))

story.append(sub("4. Fluid Resuscitation — Parkland Formula"))
story.append(info_box(
    "PARKLAND FORMULA (Gold Standard)",
    [
        "Total fluid in 24 hours = 4 mL × weight (kg) × %TBSA burned",
        "Fluid: Hartmann's solution (Ringer's lactate) — CRYSTALLOID",
        "HALF given in first 8 hours (from time of burn, NOT time of presentation)",
        "Remaining HALF given over next 16 hours",
        "Monitor: Urine output via urinary catheter — target 0.5 mL/kg/h (adults), 1 mL/kg/h (children)",
        "Example: 70 kg adult with 30% TBSA = 4×70×30 = 8400 mL; 4200 mL in first 8h, 4200 mL in next 16h",
        "Colloid (albumin) added after 8–12 hours in burns >40% TBSA",
    ],
    bg=colors.HexColor("#E8F5E8"),
    tc=GREEN
))
story.append(sp(0.1))
story.append(p(
    "<b>Resuscitation endpoint:</b> Urine output is the most reliable indicator. "
    "Avoid over-resuscitation ('fluid creep') — causes abdominal compartment syndrome and pulmonary oedema."
))

story.append(sub("5. Wound Management"))
story.append(bullet("Cover burns with clean cling film (non-adherent, transparent for monitoring, "
                    "reduces pain by keeping air from wound)"))
story.append(bullet("Do NOT apply butter, toothpaste, or other home remedies"))
story.append(bullet("Do NOT burst blisters in emergency setting"))
story.append(bullet("Formal wound cleaning and dressing in a controlled environment"))

story.append(sub("6. Additional Emergency Measures"))
story.append(bullet("<b>Analgesia:</b> IV morphine titrated; avoid intramuscular injections "
                    "(poor absorption due to peripheral shutdown)"))
story.append(bullet("<b>Nasogastric tube:</b> Insert if burns >20% TBSA (ileus expected; "
                    "Curling's ulcer prophylaxis with PPI/H2 blocker; early enteral nutrition)"))
story.append(bullet("<b>Tetanus prophylaxis:</b> Administer if not up to date"))
story.append(bullet("<b>Urinary catheter:</b> For monitoring fluid balance in burns >15–20% TBSA"))
story.append(bullet("<b>Escharotomy:</b> For circumferential full-thickness burns of limbs "
                    "(compartment syndrome) or chest (respiratory compromise); "
                    "medial and lateral incisions through eschar"))
story.append(bullet("<b>Bloods:</b> FBC, U&E, LFTs, clotting, group &amp; screen, ABG, COHb, lactate"))
story.append(bullet("<b>Warming:</b> Maintain normothermia — burned patients lose heat rapidly"))

story.append(sub("7. Criteria for Transfer to Burns Unit"))
story.append(info_box(
    "Refer to specialist burns unit if:",
    [
        "Burns >10% TBSA in adults; >5% in children",
        "Any full-thickness burn",
        "Burns involving face, hands, feet, genitalia, perineum, or major joints",
        "Circumferential burns",
        "Inhalation injury",
        "Chemical or electrical burns",
        "Burns with significant co-morbidity",
        "Suspected non-accidental injury (children)",
    ],
    bg=colors.HexColor("#FFF3E0"),
    tc=GOLD
))
story.append(sp(0.2))
story.append(p(I("Reference: Bailey &amp; Love's Short Practice of Surgery, 28th ed., Chapter 46 (Burns). "
                 "Schwartz's Principles of Surgery, 11th ed.")))

# ─── Final reference footer ──────────────────────────────────────────────────
story.append(sp(0.5))
story.append(HRFlowable(width="100%", thickness=1, color=GOLD))
story.append(sp(0.1))
story.append(Paragraph(
    "<b>References:</b> Bailey &amp; Love's Short Practice of Surgery 28th ed. | "
    "Sabiston Textbook of Surgery 21st ed. | Schwartz's Principles of Surgery 11th ed. | "
    "Robbins &amp; Kumar Basic Pathology | Cummings Otolaryngology Head and Neck Surgery | "
    "Andrews' Diseases of the Skin | Fischer's Mastery of Surgery 8th ed.",
    ref_style
))

# ─── Build ──────────────────────────────────────────────────────────────────
def on_page(canvas, doc):
    canvas.saveState()
    # Header bar
    canvas.setFillColor(BLUE)
    canvas.rect(doc.leftMargin - 0.2*cm, H - 1.5*cm,
                W - doc.leftMargin - doc.rightMargin + 0.4*cm, 0.6*cm, fill=1, stroke=0)
    canvas.setFont("Helvetica-Bold", 8)
    canvas.setFillColor(colors.white)
    canvas.drawString(doc.leftMargin, H - 1.2*cm, "MBBS Phase 3 Part 2 — Surgery Paper 1 — Model Answers")
    canvas.drawRightString(W - doc.rightMargin, H - 1.2*cm, "Reference: Bailey & Love | Sabiston | Schwartz")
    # Footer
    canvas.setFillColor(colors.grey)
    canvas.setFont("Helvetica", 7.5)
    canvas.drawCentredString(W/2, 1.2*cm, f"Page {doc.page}")
    canvas.setLineWidth(0.5)
    canvas.setStrokeColor(GOLD)
    canvas.line(doc.leftMargin, 1.5*cm, W - doc.rightMargin, 1.5*cm)
    canvas.restoreState()

doc.build(story, onFirstPage=on_page, onLaterPages=on_page)
print("PDF generated successfully.")

Successfully replaced 1 instance(s) of the string in '/tmp/workspace/surgery-paper/generate_pdf.py'