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// 4-column comparison table (Gastric vs Duodenal)
function comparisonTable() {
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  const rows = [
    ["Site", "Lesser curvature of stomach", "1st part of duodenum"],
    ["Incidence", "Less common", "More common"],
    ["Age/Sex", "Beyond 60s, M > F", "25–50 years, M > F"],
    ["H. pylori", "Less commonly associated", "Strong association"],
    ["Acid level", "Usually normal", "High (hyperchlorhydria)"],
    ["Pain & Food", "Food aggravates pain", "Food relieves pain"],
    ["Pain & Antacids", "Relief not consistent", "Prompt relief"],
    ["Night pain", "Not observed", "Common (11 PM–2 AM)"],
    ["Heartburn", "Not common", "Common"],
    ["Bleeding type", "Hematemesis more common", "Melena more common"],
    ["Vomiting", "Common", "No vomiting"],
    ["Weight loss", "Present", "Absent"],
    ["Malignancy", "Rarely undergoes malignant change", "NEVER undergoes malignant change"],
  ];
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// ─── DOCUMENT CONTENT ─────────────────────────────────────────────────────────
const doc = new Document({
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      // TITLE
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        children: [
          new TextRun({ text: "GIT PATHOLOGY", bold: true, size: 48, color: "FFFFFF", break: 0 }),
        ]
      }),
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        children: [
          new TextRun({ text: "Quick Exam Notes  |  Johari Pathology", size: 24, color: "C7D9F0" }),
        ]
      }),

      // ══════════════════════════════════════════════
      // 1. BARRETT'S ESOPHAGUS
      // ══════════════════════════════════════════════
      h1("1. BARRETT'S ESOPHAGUS"),

      h2("What is it?"),
      bullet("Intestinal metaplasia within the squamous mucosa of the esophagus."),
      bullet("Complication of chronic GERD (gastroesophageal reflux disease)."),
      bullet("Affects males, usually 40–60 years old."),

      h2("Gross Appearance"),
      bullet("One or more red, velvety tongue-like patches extending upward from the gastroesophageal (GE) junction into the esophagus."),

      h2("Microscopy"),
      boldBullet("Key finding", "Normal squamous lining of the lower esophagus is REPLACED by columnar mucosa (Columnar-Lined Esophagus / CLO)."),
      boldBullet("Goblet cells", "Mucous vacuoles present — REQUIRED for diagnosis."),
      boldBullet("Significance", "Intestinal metaplasia is an important RISK FACTOR for adenocarcinoma."),

      keyPoint("Goblet cells = MUST for diagnosis | Complication = Adenocarcinoma"),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 2. STOMACH — KEY DEFINITIONS
      // ══════════════════════════════════════════════
      h1("2. STOMACH — KEY DEFINITIONS"),
      twoColTable([
        ["Erosion", "Loss of superficial epithelium → small mucosal defect LIMITED to lamina propria (does NOT penetrate muscularis mucosae)"],
        ["Ulcer", "Break in mucosal surface > 5 mm in size, WITH DEPTH — penetrates muscularis mucosae. Leads to local excavation."],
        ["Gastritis", "Inflammation of gastric mucosa — usually a histological diagnosis."],
        ["Gastropathy", "Used when inflammatory cells are rare or absent (e.g., hypertrophic gastropathy)."],
      ]),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 3. GASTRITIS
      // ══════════════════════════════════════════════
      h1("3. GASTRITIS"),

      h2("Classification"),
      twoColTable([
        ["Acute Gastritis", "Short-term mucosal inflammation. Caused by: NSAIDs, alcohol, stress, H. pylori."],
        ["Chronic Gastritis", "Long-term inflammation. Most common cause = H. pylori infection."],
        ["Type A (Autoimmune)", "Autoimmune — affects body/fundus. Associated with pernicious anemia. Anti-parietal cell antibodies present."],
        ["Type B (H. pylori)", "Most common type. Affects antrum. H. pylori is the main cause."],
      ], "Type", "Description"),
      emptyLine(),
      keyPoint("H. pylori = Most common cause of chronic gastritis (Type B, antrum)"),
      keyPoint("Type A = Autoimmune → Pernicious anemia → Anti-parietal cell Abs"),
      emptyLine(),

      h2("H. pylori — Key Facts"),
      bullet("Gram-negative rod."),
      bullet("Found in the gastric mucus overlying surface epithelium."),
      bullet("Produces urease → splits urea → produces ammonia → damages mucosa."),
      bullet("Diagnosis: Urea breath test, CLO test (rapid urease test), biopsy, serology, stool antigen."),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 4. PEPTIC ULCER DISEASE
      // ══════════════════════════════════════════════
      h1("4. PEPTIC ULCER DISEASE (PUD)"),

      h2("Definition"),
      bullet("Chronic mucosal ulceration that PENETRATES the muscularis mucosae."),
      bullet("Affects: Duodenum (most common site) or stomach."),
      bullet("Most often associated with: H. pylori infection, NSAIDs, cigarette smoking."),

      h2("Damaging vs. Defensive Forces"),
      twoColTable([
        ["Damaging Forces", "Gastric acidity (HCl), peptic enzymes (pepsin), H. pylori, NSAIDs, direct mucosal damage"],
        ["Defensive Forces", "Mucus-bicarbonate layer (pre-epithelial), surface epithelial cell regeneration (epithelial), mucosal blood flow (subepithelial), prostaglandins"],
      ], "Side", "Components"),
      emptyLine(),

      h2("4 Microscopic Zones of Ulcer (from surface to base)"),
      boldBullet("Zone 1", "Necrotic debris (fibrinous, PMNs)"),
      boldBullet("Zone 2", "Non-specific inflammatory exudate with neutrophils"),
      boldBullet("Zone 3", "Granulation tissue with mononuclear leukocytes"),
      boldBullet("Zone 4", "Fibrous/collagenous scar — forms the ulcer BASE"),

      h2("Clinical Features"),
      bullet("Age: Young adults, but more commonly diagnosed in middle-aged/elderly."),
      bullet("Pain: Epigastric burning/aching — worse on fasting, better with food/antacids."),
      bullet("Timing: 1–3 hours after meals; night pain 11 PM–2 AM."),
      bullet("Other: Nausea, vomiting, bloating, belching, weight loss."),

      h2("Complications of PUD"),
      boldBullet("Bleeding", "MOST COMMON complication. Chronic loss → iron deficiency anemia. Severe → 'coffee ground' vomitus / melena."),
      boldBullet("Perforation", "~5% of patients. Most common complication of gastric ulcer."),
      boldBullet("Pyloric obstruction", "~10% of ulcer patients. Due to edema or scarring. Gastric outlet obstruction."),
      boldBullet("Malignancy", "Duodenal ulcers NEVER become malignant. Small % of gastric ulcers may transform."),

      keyPoint("Most common complication = BLEEDING | Perforation = most common of gastric ulcer"),
      keyPoint("Duodenal ulcer NEVER undergoes malignant transformation"),
      emptyLine(),

      // Gastric vs Duodenal Ulcer comparison
      h2("Gastric Ulcer vs. Duodenal Ulcer — Comparison Table"),
      comparisonTable(),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 5. GASTRIC CARCINOMA
      // ══════════════════════════════════════════════
      h1("5. GASTRIC CARCINOMA"),

      h2("Key Points"),
      bullet("Adenocarcinoma = most common malignancy of stomach."),
      bullet("Incidence DECREASING in developed countries due to refrigeration (less smoked/preserved food)."),

      h2("Risk Factors"),
      h3("Environmental Factors"),
      bullet("H. pylori infection (5–6× increased risk)"),
      bullet("Dietary: Nitrites (from nitrates), smoked/salted foods, excess salt"),
      bullet("Low socioeconomic status (high carbohydrate diet)"),
      bullet("Rubber and coal workers"),

      h3("Host/Genetic Factors"),
      bullet("Blood group A"),
      bullet("Family history of gastric cancer"),

      h3("Predisposing Conditions"),
      bullet("Chronic gastritis → intestinal metaplasia (precursor lesion) → dysplasia → carcinoma"),
      bullet("Gastric polyps, previous gastric surgery"),

      h3("Protective Factors (Decreased Risk)"),
      bullet("Aspirin"),
      bullet("Diet rich in fresh fruits and vegetables"),
      bullet("Vitamins A and C"),
      bullet("Calcium, selenium, zinc, iron"),
      keyPoint("ALCOHOL is NOT a risk factor for gastric carcinoma"),

      h2("Pathogenesis (H. pylori Sequence)"),
      bullet("H. pylori infection → mucosal inflammation → hypochlorhydria → bacterial growth → mucosal atrophy → intestinal metaplasia → dysplasia → Carcinoma"),

      h2("Lauren Classification (Histologic)"),
      twoColTable([
        ["INTESTINAL TYPE",
         "• Polypoid/bulky tumors or ulcerated\n• Cohesive tumor cells forming gland-like tubular structures (like colon adenocarcinoma)\n• Apical mucin vacuoles\n• Better prognosis"],
        ["DIFFUSE (INFILTRATING) TYPE",
         "• No obvious mass — infiltrates diffusely\n• Involves broad region/entire stomach\n• Desmoplastic reaction → rigid wall\n• If entire stomach involved → 'Linitis Plastica' (leather bottle stomach)\n• Discohesive cells (loss of E-cadherin)\n• Signet-ring cells: mucin pushes nucleus to periphery\n• If signet-ring cells >50% = Signet-Ring Cell Carcinoma\n• Worse prognosis"],
      ], "Type", "Features"),
      emptyLine(),
      keyPoint("Linitis Plastica = Diffuse type → leather bottle stomach"),
      keyPoint("Signet-ring cell = mucin fills cytoplasm, nucleus pushed to side"),
      keyPoint("E-cadherin loss → discohesive cells in diffuse type"),
      emptyLine(),

      h2("Gross Morphology Types"),
      bullet("Type 1: Polypoid"),
      bullet("Type 2: Fungating"),
      bullet("Type 3: Ulcerated"),
      bullet("Type 4: Infiltrative"),

      h2("Early Gastric Cancer"),
      bullet("Defined as: Cancer confined to mucosa and submucosa — IRRESPECTIVE of node status."),
      keyPoint("Early gastric cancer = confined to mucosa/submucosa regardless of lymph node status"),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 6. ULCERATIVE COLITIS
      // ══════════════════════════════════════════════
      h1("6. ULCERATIVE COLITIS (UC)"),

      h2("Basic Features"),
      bullet("Chronic inflammatory bowel disease (IBD)."),
      bullet("Affects: Rectum → extends proximally (continuous, no skip lesions)."),
      bullet("Confined to mucosa and superficial submucosa (NOT full-thickness)."),
      bullet("Bowel wall is NOT thickened; no strictures."),

      h2("Gross Appearance"),
      bullet("Mucosal surface is congested, red, and bleeds easily."),
      bullet("Ulcers aligned along the long axis of colon (NOT serpentine like Crohn's)."),
      boldBullet("Pseudopolyps (Inflammatory polyps)", "In longstanding disease — isolated regenerating mucosa islands bulge into lumen, appearing as small elevations."),
      keyPoint("Continuous lesion from rectum. Sharp demarcation between involved and normal mucosa."),

      h2("Microscopy"),
      h3("Early Active Colitis"),
      bullet("Mucosal congestion, edema, microscopic hemorrhages."),
      bullet("Chronic inflammatory infiltrate: lymphocytes, plasma cells, macrophages."),
      bullet("Neutrophils invade crypts → Cryptitis → Crypt abscess (hallmark!)."),

      h3("Resolution Phase"),
      bullet("Decreased activity, crypt regeneration."),

      h2("Serious Complication"),
      boldBullet("Toxic Megacolon", "Severe inflammation damages muscularis propria → loss of neuromuscular function → colonic dilation → perforation risk."),
      boldBullet("Cancer Risk", "Increased risk of colorectal carcinoma in longstanding UC (>10 years, extensive disease)."),
      emptyLine(),
      keyPoint("Crypt abscess = hallmark of UC | Continuous from rectum | No skip lesions | Full-thickness NOT involved"),
      emptyLine(),

      // Crohn's vs UC mini-table
      h2("UC vs. Crohn's Disease — Quick Comparison"),
      twoColTable([
        ["Distribution", "Rectum → colon (continuous)", "Any part of GIT (skip lesions)"],
        ["Depth", "Mucosa + superficial submucosa only", "Transmural (full-thickness)"],
        ["Ulcers", "Along long axis", "Serpentine/cobblestone appearance"],
        ["Bowel wall", "Not thickened", "Thickened; strictures common"],
        ["Fistulae", "Rare", "Common"],
        ["Granulomas", "Absent", "Non-caseating granulomas (hallmark)"],
        ["Cancer risk", "High (longstanding UC)", "Lower than UC"],
      ], "Feature", "UC / Crohn's"),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 7. COLORECTAL CARCINOMA
      // ══════════════════════════════════════════════
      h1("7. COLORECTAL CARCINOMA"),

      h2("Gross Appearance"),
      bullet("Right-sided (proximal colon): Polypoid / cauliflower mass — grows into the lumen."),
      bullet("Left-sided (distal colon): Annular / napkin-ring lesion — encircles the colon."),
      bullet("Ulcerated type: Raised, irregular edges with central excavated ulcerated area; infiltrates deep layers."),

      h2("Microscopy"),
      bullet("Glands of variable size and configuration, separated by moderate stroma."),
      bullet("Mitotic figures abundant."),
      bullet("Lumen filled with inspissated eosinophilic mucus + necrotic debris = 'DIRTY NECROSIS' (characteristic!)."),
      bullet("Poorly differentiated carcinoma = few glands."),
      boldBullet("Signet-ring cell carcinoma", "Signet-ring cells >50% of tumor (similar to gastric signet-ring carcinoma)."),

      keyPoint("'Dirty necrosis' = inspissated mucus + cellular debris in gland lumen — hallmark of colorectal adenocarcinoma"),

      h2("Clinical Features"),
      boldBullet("Right-sided", "Fatigue and weakness → iron deficiency anemia (occult bleeding)."),
      boldBullet("Left-sided", "Occult bleeding, altered bowel habits, left lower quadrant pain/discomfort."),

      h2("Investigations"),
      bullet("Guaiac test — detect occult blood in stool."),
      bullet("Tumor marker: CEA (carcinoembryonic antigen) — elevated."),
      bullet("Flexible sigmoidoscopy."),
      bullet("Colonoscopy — direct visualization."),
      boldBullet("Investigation of CHOICE", "Biopsy."),
      emptyLine(),

      // ══════════════════════════════════════════════
      // 8. VIRAL HEPATITIS
      // ══════════════════════════════════════════════
      h1("8. VIRAL HEPATITIS"),

      h2("Definition"),
      bullet("Viral infection of hepatocytes producing necrosis and inflammation of the liver."),
      bullet("Causative agents (Hepatotropic viruses): A, B, C, D, E."),
      boldBullet("Important fact", "ALL hepatitis viruses EXCEPT HBV are RNA viruses. HBV is a DNA virus."),

      h2("Quick Classification"),
      twoColTable([
        ["Hepatitis A & E", "Infectious hepatitis. Transmitted via fecal-oral route. Do NOT cause chronic hepatitis."],
        ["Hepatitis B, C, D", "Serum hepatitis. Transmitted via blood/body fluids. CAN cause chronic hepatitis."],
        ["HBV", "DNA virus (only one). Can cause: Acute, Chronic, Cirrhosis, Hepatocellular carcinoma."],
        ["HCV", "RNA virus. Most common cause of post-transfusion hepatitis. High rate of chronicity (~85%)."],
        ["HDV", "Defective RNA virus — requires HBV for infection (co-infection or superinfection)."],
      ], "Virus", "Key Points"),
      emptyLine(),
      keyPoint("HBV = ONLY DNA hepatitis virus. All others = RNA"),
      keyPoint("HDV needs HBV to survive — co-infection vs. superinfection"),
      keyPoint("HCV = most chronic (85%) and most common post-transfusion hepatitis"),
      emptyLine(),

      // ─── QUICK REVISION SUMMARY ──────────────────
      h1("QUICK REVISION — HIGH-YIELD POINTS"),

      new Paragraph({
        spacing: { before: 60, after: 80 },
        shading: { type: ShadingType.SOLID, color: "FFF2CC" },
        children: [new TextRun({ text: "Must-Know Facts for Exam", bold: true, size: 22, color: "7F4F00" })]
      }),

      bullet("Barrett's Esophagus: Goblet cells = must for Dx | Risk = Adenocarcinoma"),
      bullet("Erosion: limited to lamina propria. Ulcer: penetrates muscularis mucosae."),
      bullet("H. pylori = #1 cause of chronic gastritis (Type B, antrum)"),
      bullet("Peptic ulcer most common complication = BLEEDING"),
      bullet("Duodenal ulcer NEVER → malignant. Gastric ulcer → rarely malignant."),
      bullet("Linitis Plastica = diffuse gastric cancer → leather bottle stomach"),
      bullet("Signet-ring cells: mucin pushes nucleus to periphery"),
      bullet("Early gastric cancer = confined to mucosa/submucosa (regardless of nodes)"),
      bullet("UC = continuous from rectum, no skip lesions, mucosa only, crypt abscesses"),
      bullet("UC hallmark = Crypt abscess | Crohn's hallmark = Non-caseating granuloma"),
      bullet("Dirty necrosis = hallmark of colorectal adenocarcinoma"),
      bullet("Right colon cancer → anemia (occult bleed); Left colon cancer → obstruction"),
      bullet("HBV = ONLY DNA virus among hepatitis viruses"),
      bullet("HCV = highest chronicity rate (85%) + most common post-transfusion hepatitis"),
      bullet("HDV = defective virus, needs HBV"),
      emptyLine(),
    ]
  }]
});

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