Write 10 mark answer on t and nk cell lymphoma which consist of ethology, genetics,microscopy, cd marker and prognosis

Reading File

Finding Sources

Reading File

Finding Sources

Reading File

Loading Image

I now have all the information needed for a comprehensive 10-mark answer. Let me compose the full structured answer.

T and NK Cell Lymphoma

Introduction

T and NK cell lymphomas are a heterogeneous group of mature (peripheral) lymphoid neoplasms derived from post-thymic T lymphocytes or natural killer (NK) cells. They are collectively called peripheral T-cell neoplasms and account for roughly 10-15% of all non-Hodgkin lymphomas (NHLs) in Western countries, with higher rates in Asia. As a group, they carry a significantly worse prognosis than comparably aggressive B-cell neoplasms.

Classification (WHO)

The major subtypes covered here are:

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) - the most common subtype, a "wastebasket" category
Extranodal NK-/T-cell lymphoma, nasal type - strongly EBV-associated
Anaplastic large-cell lymphoma (ALCL), ALK-positive and ALK-negative
Adult T-cell leukemia/lymphoma (ATL) - HTLV-1 driven
Nodal T-follicular helper cell lymphoma (angioimmunoblastic type)

Etiology

Subtype	Etiological Agent
Extranodal NK-/T-cell lymphoma	Epstein-Barr virus (EBV) - all tumor cells contain identical EBV episomes; clonal EBV infection from a single infected cell
Adult T-cell leukemia/lymphoma	HTLV-1 (Human T-cell Leukemia Virus type 1) - endemic in southern Japan, West Africa, and the Caribbean basin
ALCL (ALK+)	No viral association; occurs in children/young adults; chromosomal translocations drive oncogenesis
PTCL-NOS	No single etiology; multifactorial
Nodal T-follicular helper cell lymphoma	Associated with underlying clonal hematopoiesis; EBV-positive B-cell proliferations frequently co-exist

Key note on NK/T-cell lymphoma: EBV entry into NK cells is unusual since these cells lack CD21 (the B-cell EBV receptor), so the mechanism of viral entry remains uncertain. Racial predisposition exists - it is prevalent in Asian and Native American populations of Central and South America.

Genetics

Extranodal NK-/T-Cell Lymphoma

Multiple chromosomal aberrations are present but none are specific
Recurrent mutations in:
- JAK/STAT pathway genes (driving proliferation and survival)
- Epigenetic regulators
- TP53 tumor suppressor gene
No T-cell receptor (TCR) gene rearrangements (confirming NK cell origin in most)

ALCL (ALK-Positive) - The Key Genetic Lesion

Rearrangements of the ALK gene on chromosome 2p23
Classic translocation: t(2;5)(p23;q35) - fuses ALK (tyrosine kinase) with NPM (nucleophosmin), creating a constitutively active NPM-ALK fusion protein
This fusion protein activates RAS and JAK/STAT signaling pathways
Variant ALK translocations also occur
ALK is not expressed in normal lymphocytes, so its detection is highly specific

Adult T-Cell Leukemia/Lymphoma (ATL)

Tumor cells always contain clonal HTLV-1 proviruses
Acquired mutations in TP53 and CDKN2A are common in aggressive forms
Acquired chromosomal copy number variants accumulate over years

Nodal T-Follicular Helper Cell Lymphoma

Most commonly mutated genes: TET2 and DNMT3A (same genes mutated in clonal hematopoiesis)
The lymphoma and circulating myeloid cells often share identical mutations, suggesting origin from a mutated hematopoietic stem cell

PTCL-NOS

Clonal TCR gene rearrangements - used for diagnosis in difficult cases
No pathognomonic genetic lesion

Microscopy (Histopathology)

PTCL-NOS

A pleomorphic mixture of variably sized malignant T cells that diffusely efface lymph nodes. Prominent reactive infiltrate of eosinophils and macrophages (attracted by tumor-derived cytokines) is characteristic. Brisk neoangiogenesis is also frequently seen.

PTCL-NOS: A spectrum of small, intermediate, and large lymphoid cells with irregular nuclear contours (Robbins Pathology)

Extranodal NK-/T-Cell Lymphoma

Presents as a destructive nasopharyngeal mass
Tumor cell infiltrate surrounds and invades small vessels (angioinvasion) - leading to extensive ischemic necrosis
In touch preparations, large azurophilic granules in cytoplasm (resembling normal NK cell granules)
Cells range from small to large

Anaplastic Large-Cell Lymphoma (ALCL)

Large anaplastic cells with abundant cytoplasm
Characteristic "hallmark cells" with horseshoe-shaped or embryoid nuclei
Cells often cluster around venules and infiltrate lymphoid sinuses (may mimic metastatic carcinoma)
May show wreath-like multilobulated nuclei

ALCL: (A) Hallmark cells with horseshoe nuclei and abundant cytoplasm. (B) IHC showing ALK fusion protein (brown staining)

ALCL: (A) Hallmark cells with horseshoe-like/embryoid nuclei. (B) IHC for ALK fusion protein. (Robbins Pathology)

Adult T-Cell Leukemia/Lymphoma (ATL)

Variable morphology
Characteristic "flower cells" or "cloverleaf cells" - multilobated nuclei in peripheral blood

CD Markers (Immunophenotype)

Subtype	Positive Markers	Negative / Variable
PTCL-NOS	CD2, CD3, CD5 (pan-T); CD45RO, CD43; CD4+ (more common than CD8+)	One or more pan-T antigens aberrantly lost; CD68 rarely positive
Extranodal NK-/T-Cell Lymphoma	CD56 (NK marker), cytoplasmic CD3ε, EBV (EBER+), cytotoxic granule proteins (TIA-1, granzyme B)	Surface CD3− (no TCR gene rearrangements), CD16−, CD21−
ALCL (ALK+)	CD30 (universally positive; Ki-1), ALK protein (nuclear and cytoplasmic with t(2;5)); variable CD3, CD5, CD4, CD43, CD45RO; CD25, EMA sometimes positive	CD3 often negative; surface T-cell markers often lost
ALCL (ALK-)	CD30 (universally positive)	ALK negative; generally similar phenotype to ALK+
ATL	CD4+, CD3+, CD2+, CD25 (IL-2 receptor, strongly positive)	CD8−
Nodal T-follicular helper cell lymphoma	CD4+, BCL6, PD-1, CXCL13, ICOS, CD10 (Tfh markers)	-

Key CD marker summary:

CD56 is the hallmark NK cell marker
CD30 is the hallmark of ALCL
CD25 (IL-2 receptor alpha) is strongly expressed in ATL
Cytoplasmic CD3ε (not surface CD3) is expressed in NK-cell lymphoma
Loss of normal pan-T antigens (CD3, CD5, CD7) is a clue to malignancy in PTCL-NOS

Prognosis

Subtype	Prognosis	Notes
ALCL (ALK+)	Good - 5-year survival ~75-80%	Best prognosis among T-cell lymphomas; ALK inhibitors effective in chemotherapy-resistant cases
ALCL (ALK-)	Intermediate-poor	Substantially worse than ALK+; CD30 targeted therapy (brentuximab vedotin) effective
PTCL-NOS	Poor	Significantly worse than comparably aggressive B-cell lymphomas (e.g., DLBCL); cures reported but rare
Extranodal NK-/T-cell lymphoma	Poor (advanced disease)	Responds to radiation therapy for localized disease; relatively chemotherapy-resistant; allogeneic HSCT and immune checkpoint inhibitors offer hope in advanced disease
ATL	Very poor	Highly aggressive; median survival months in acute form; smoldering/chronic forms indolent
Nodal T-follicular helper cell lymphoma	Intermediate-poor	Median OS ~3 years with standard chemotherapy

Prognostic factors in T/NK-cell lymphoma:

ALK positivity in ALCL is the single most important good prognostic indicator
EBV positivity in NK-/T-cell lymphoma is a marker of aggressive behavior
Advanced stage, elevated LDH, poor performance status all worsen prognosis
Localized NK-/T-cell lymphoma treated with concurrent chemoradiation (CCRT) using L-asparaginase-based regimens (SMILE protocol) has improved outcomes

Summary Table

Feature	PTCL-NOS	NK-/T-cell Lymphoma	ALCL (ALK+)	ATL
Etiology	None specific	EBV	Chromosomal t(2;5)	HTLV-1
Key gene	TCR rearrangement	JAK/STAT, TP53	NPM-ALK fusion	TP53, CDKN2A
Morphology	Pleomorphic, mixed cells	Angioinvasive, necrosis, azurophilic granules	Hallmark cells, horseshoe nuclei	Flower/cloverleaf cells
Key CD markers	CD2, CD3, CD5 (aberrant loss)	CD56+, cCD3ε+, surface CD3−	CD30+, ALK+	CD4+, CD25+
Prognosis	Poor	Poor (advanced)	Good (75-80% CR)	Very poor

Sources: Robbins, Cotran & Kumar - Pathologic Basis of Disease; Henry's Clinical Diagnosis and Management by Laboratory Methods; Quick Compendium of Clinical Pathology 5th edition

Create a 10 marker PDF for NK-cell sarcoma in md pathology exam which include types etiology microscopy cd marker and prognosis according latest who classification

Reading File

Finding Sources

Reading File

Searching the Web

NK cell neoplasms WHO 5th edition 2022 classification extranodal NK/T cell lymphoma nasal type aggressive NK cell leukemia

Running Command

ls -la /tmp/workspace/ 2>/dev/null || mkdir -p /tmp/workspace && ls -la /tmp/workspace/

Running Command

mkdir -p /tmp/workspace/nk-cell-lymphoma && cat > /tmp/workspace/nk-cell-lymphoma/make_pdf.py << 'PYEOF' from reportlab.lib.pagesizes import A4 from reportlab.lib import colors from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm, mm from reportlab.platypus import (SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable, KeepTogether) from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY from reportlab.pdfbase import pdfmetrics from reportlab.pdfbase.ttfonts import TTFont OUTPUT = "/tmp/workspace/nk-cell-lymphoma/NK_Cell_Lymphoma_10_Mark.pdf" # ── Colours ────────────────────────────────────────────────────────────────── DARK_BLUE = colors.HexColor("#0D2B55") MED_BLUE = colors.HexColor("#1A4E8C") LIGHT_BLUE = colors.HexColor("#D6E8FF") ACCENT = colors.HexColor("#C0392B") LIGHT_GREY = colors.HexColor("#F4F6F8") MID_GREY = colors.HexColor("#BDC3C7") WHITE = colors.white BLACK = colors.black doc = SimpleDocTemplate( OUTPUT, pagesize=A4, leftMargin=2*cm, rightMargin=2*cm, topMargin=2*cm, bottomMargin=2*cm ) styles = getSampleStyleSheet() # ── Custom styles ──────────────────────────────────────────────────────────── def S(name, **kw): return ParagraphStyle(name, **kw) title_style = S("Title", fontName="Helvetica-Bold", fontSize=18, textColor=WHITE, alignment=TA_CENTER, leading=22, spaceAfter=4) subtitle_style = S("Subtitle", fontName="Helvetica", fontSize=10, textColor=LIGHT_BLUE, alignment=TA_CENTER, leading=14, spaceAfter=2) badge_style = S("Badge", fontName="Helvetica-Bold", fontSize=9, textColor=WHITE, alignment=TA_CENTER) section_head = S("SectionHead", fontName="Helvetica-Bold", fontSize=12, textColor=WHITE, alignment=TA_LEFT, leading=16) body = S("Body", fontName="Helvetica", fontSize=9.5, textColor=BLACK, leading=14, alignment=TA_JUSTIFY, spaceAfter=4) body_bold = S("BodyBold", fontName="Helvetica-Bold", fontSize=9.5, textColor=BLACK, leading=14, alignment=TA_LEFT) bullet_style = S("Bullet", fontName="Helvetica", fontSize=9.5, textColor=BLACK, leading=13, leftIndent=12, bulletIndent=0, spaceAfter=2) sub_bullet = S("SubBullet", fontName="Helvetica", fontSize=9, textColor=colors.HexColor("#333333"), leading=12, leftIndent=24, bulletIndent=12, spaceAfter=1) table_head_style = S("TableHead", fontName="Helvetica-Bold", fontSize=8.5, textColor=WHITE, alignment=TA_CENTER, leading=11) table_body_style = S("TableBody", fontName="Helvetica", fontSize=8.5, textColor=BLACK, alignment=TA_LEFT, leading=11) footer_style = S("Footer", fontName="Helvetica-Oblique", fontSize=7.5, textColor=colors.HexColor("#777777"), alignment=TA_CENTER) key_point_style = S("KeyPoint", fontName="Helvetica-BoldOblique", fontSize=9, textColor=ACCENT, leading=13, leftIndent=8) # ── Helper: section header block ───────────────────────────────────────────── def section_header(text, color=MED_BLUE): tbl = Table([[Paragraph(text, section_head)]], colWidths=[17*cm]) tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,-1), color), ("TOPPADDING", (0,0), (-1,-1), 5), ("BOTTOMPADDING", (0,0), (-1,-1), 5), ("LEFTPADDING", (0,0), (-1,-1), 10), ("ROUNDEDCORNERS", [4,4,4,4]), ])) return tbl def note_box(text, bg=LIGHT_BLUE): tbl = Table([[Paragraph(text, S("nb", fontName="Helvetica", fontSize=9, textColor=DARK_BLUE, leading=13, leftIndent=4))]], colWidths=[17*cm]) tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,-1), bg), ("TOPPADDING", (0,0), (-1,-1), 6), ("BOTTOMPADDING", (0,0), (-1,-1), 6), ("LEFTPADDING", (0,0), (-1,-1), 12), ("BOX", (0,0), (-1,-1), 1, MED_BLUE), ])) return tbl def sp(n=6): return Spacer(1, n) # ═══════════════════════════════════════════════════════════════════════════ # TITLE BANNER # ═══════════════════════════════════════════════════════════════════════════ def title_banner(): banner = Table( [[Paragraph("T / NK Cell Lymphoma", title_style)], [Paragraph("MD Pathology Examination • 10 Marks", subtitle_style)], [Paragraph("Based on WHO Classification of Haematolymphoid Tumours 5th Edition (2022)", subtitle_style)]], colWidths=[17*cm] ) banner.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,-1), DARK_BLUE), ("TOPPADDING", (0,0), (-1,-1), 10), ("BOTTOMPADDING", (0,0), (-1,-1), 10), ("LEFTPADDING", (0,0), (-1,-1), 10), ("BOX", (0,0), (-1,-1), 2, MED_BLUE), ])) return banner # ═══════════════════════════════════════════════════════════════════════════ # BUILD CONTENT # ═══════════════════════════════════════════════════════════════════════════ story = [] story.append(title_banner()) story.append(sp(14)) # ── INTRO ───────────────────────────────────────────────────────────────── story.append(section_header("INTRODUCTION")) story.append(sp(5)) story.append(Paragraph( "T and NK cell lymphomas are a heterogeneous group of mature (peripheral) lymphoid neoplasms " "derived from post-thymic T lymphocytes or natural killer (NK) cells. They account for " "10–15% of all Non-Hodgkin Lymphomas (NHLs) in Western countries, with significantly " "higher rates (~25–35%) in Asia. As a group, they carry a worse prognosis than comparably " "aggressive B-cell neoplasms such as DLBCL.", body)) story.append(sp(8)) # ── WHO 2022 CLASSIFICATION ─────────────────────────────────────────────── story.append(section_header("WHO 5th EDITION (2022) — NK-CELL NEOPLASM TYPES", MED_BLUE)) story.append(sp(5)) who_data = [ [Paragraph("WHO 2022 Entity", table_head_style), Paragraph("Key Feature", table_head_style), Paragraph("Behaviour", table_head_style)], [Paragraph("Extranodal NK/T-cell lymphoma (ENKTL)\n[\"nasal type\" qualifier REMOVED in WHO-5]", table_body_style), Paragraph("EBV+, nasal & extranasal sites, angioinvasive", table_body_style), Paragraph("Aggressive", table_body_style)], [Paragraph("Aggressive NK-cell leukaemia (ANKL)", table_body_style), Paragraph("EBV+, systemic, leukemic picture; includes intravascular NK/T-cell lymphoma (now moved here from WHO-4R)", table_body_style), Paragraph("Very aggressive", table_body_style)], [Paragraph("Chronic lymphoproliferative disorder of NK cells (CLPD-NK)", table_body_style), Paragraph("Indolent, persistent NK-cell lymphocytosis", table_body_style), Paragraph("Indolent", table_body_style)], [Paragraph("Indolent NK-cell lymphoproliferative disorder of GI tract (provisional)", table_body_style), Paragraph("Localised GI mucosal NK-cell infiltrates", table_body_style), Paragraph("Indolent", table_body_style)], [Paragraph("EBV-positive nodal NK-cell lymphoma", table_body_style), Paragraph("NEW entity in WHO-5; nodal presentation", table_body_style), Paragraph("Aggressive", table_body_style)], [Paragraph("Hydroa vacciniforme lymphoproliferative disorder (HV-LPD)", table_body_style), Paragraph("EBV+; children in Asia/Latin America; UV-exacerbated skin lesions", table_body_style), Paragraph("Variable", table_body_style)], ] who_tbl = Table(who_data, colWidths=[6*cm, 7.5*cm, 3.5*cm]) who_tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,0), DARK_BLUE), ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, LIGHT_GREY]), ("TEXTCOLOR", (0,0), (-1,0), WHITE), ("GRID", (0,0), (-1,-1), 0.5, MID_GREY), ("TOPPADDING", (0,0), (-1,-1), 5), ("BOTTOMPADDING", (0,0), (-1,-1), 5), ("LEFTPADDING", (0,0), (-1,-1), 6), ("VALIGN", (0,0), (-1,-1), "TOP"), ])) story.append(who_tbl) story.append(sp(4)) story.append(note_box( "⭐ WHO-5 KEY CHANGE: 'Nasal type' qualifier dropped from ENKTL name — disease can arise at any extranodal site. " "Intravascular NK/T-cell lymphoma reclassified under ANKL. EBV-positive nodal NK-cell lymphoma is a NEW entity." )) story.append(sp(10)) # ── ETIOLOGY ───────────────────────────────────────────────────────────── story.append(section_header("ETIOLOGY")) story.append(sp(5)) etio_data = [ [Paragraph("Entity", table_head_style), Paragraph("Etiological Agent / Mechanism", table_head_style)], [Paragraph("Extranodal NK/T-cell lymphoma (ENKTL)", table_body_style), Paragraph("Epstein-Barr Virus (EBV) — all tumor cells carry clonal EBV episomes indicating origin from a single EBV-infected cell. Entry mechanism is unclear as NK cells LACK CD21 (the EBV B-cell receptor). EBV latency type II pattern (LMP1/LMP2A expression).", table_body_style)], [Paragraph("Aggressive NK-cell leukaemia (ANKL)", table_body_style), Paragraph("EBV+ (not universal). JAK/STAT & RAS/MAPK pathway mutations. Epigenetic modifier mutations (TET2, CREBBP, KMT2D). PD-L1/PD-L2 alterations drive immune evasion.", table_body_style)], [Paragraph("HV-LPD", table_body_style), Paragraph("EBV infection in childhood. UV light exacerbates lesions. Mosquito bite hypersensitivity is associated (mosquito salivary gland antigens contain EBV-stimulating proteins).", table_body_style)], ] etio_tbl = Table(etio_data, colWidths=[5.5*cm, 11.5*cm]) etio_tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,0), DARK_BLUE), ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, LIGHT_GREY]), ("GRID", (0,0), (-1,-1), 0.5, MID_GREY), ("TOPPADDING", (0,0), (-1,-1), 5), ("BOTTOMPADDING", (0,0), (-1,-1), 5), ("LEFTPADDING", (0,0), (-1,-1), 6), ("VALIGN", (0,0), (-1,-1), "TOP"), ])) story.append(etio_tbl) story.append(sp(5)) story.append(Paragraph("Epidemiology:", body_bold)) story.append(Paragraph( "• ENKTL: Prevalent in East Asians and Native Americans of Central/South America. " "Accounts for 2–11% of all lymphomas in East Asia vs. <1% in the West. " "Median age 52–58 years. Male:female = 1.5:1.", bullet_style)) story.append(Paragraph( "• ANKL: Rarer (~1/6th incidence of ENKTL); fulminant onset, often in young adults.", bullet_style)) story.append(Paragraph( "• Genetic predisposition: EBV-specific immune response variants (HLA-A, B, C genes) influence susceptibility.", bullet_style)) story.append(sp(10)) # ── MICROSCOPY ─────────────────────────────────────────────────────────── story.append(section_header("MICROSCOPY (HISTOPATHOLOGY)")) story.append(sp(5)) story.append(Paragraph("1. Extranodal NK/T-cell Lymphoma (ENKTL)", body_bold)) story.append(sp(3)) micro_items_enktl = [ ("Pattern", "Diffuse lymphoid infiltrate effacing normal tissue architecture."), ("Angioinvasion", "Tumor cells surround and invade small to medium vessel walls — the hallmark feature. Leads to extensive ischemic (coagulative) necrosis."), ("Cell morphology", "Spectrum from small to large neoplastic cells. Medium-sized cells predominate with irregular, angulated nuclei, moderately condensed chromatin, and pale cytoplasm."), ("Granules", "On touch preparations: large azurophilic (reddish-purple) cytoplasmic granules — identical to normal NK cell granules."), ("Background", "Mixed inflammatory background with neutrophils, plasma cells, histiocytes. Mucosal ulceration is characteristic."), ("Special stain", "EBER (EBV-encoded RNA) in-situ hybridisation (ISH) is positive in virtually all cases — diagnostic gold standard."), ] for label, text in micro_items_enktl: story.append(Paragraph(f"{label}: {text}", bullet_style)) story.append(sp(7)) story.append(Paragraph("2. Aggressive NK-cell Leukaemia (ANKL)", body_bold)) story.append(sp(3)) for item in [ "Peripheral blood and bone marrow infiltration by large granular lymphocytes.", "Cells have irregular, folded nuclei with prominent nucleoli and pale cytoplasm with azurophilic granules.", "Hemophagocytosis (macrophages engulfing blood cells) frequently seen in bone marrow — associated hemophagocytic lymphohistiocytosis (HLH).", "Liver/spleen diffusely infiltrated in sinusoids.", ]: story.append(Paragraph(f"• {item}", bullet_style)) story.append(sp(7)) story.append(Paragraph("3. HV-LPD (Cutaneous NK/T-cell)", body_bold)) story.append(sp(3)) for item in [ "Dermis and subcutaneous fat infiltrated by intermediate-sized, atypical granular lymphocytes within and around walls of small and medium vessels.", "Epidermotropism may be noted.", "Papulovesicular lesions with scarring on sun-exposed areas (face and extremities).", ]: story.append(Paragraph(f"• {item}", bullet_style)) story.append(sp(10)) # ── CD MARKERS ─────────────────────────────────────────────────────────── story.append(section_header("IMMUNOPHENOTYPE (CD MARKERS)")) story.append(sp(5)) cd_data = [ [Paragraph("Marker", table_head_style), Paragraph("ENKTL", table_head_style), Paragraph("ANKL", table_head_style), Paragraph("CLPD-NK", table_head_style), Paragraph("HV-LPD", table_head_style)], [Paragraph("CD2", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("Variable", table_body_style)], [Paragraph("Surface CD3", table_body_style), Paragraph("✗ NEGATIVE", S("n",fontName="Helvetica-Bold",fontSize=8.5,textColor=ACCENT,leading=11)), Paragraph("✗ Negative", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("Variable", table_body_style)], [Paragraph("Cytoplasmic CD3ε", table_body_style), Paragraph("✓ POSITIVE", S("p",fontName="Helvetica-Bold",fontSize=8.5,textColor=colors.HexColor("#1A7A1A"),leading=11)), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style)], [Paragraph("CD4", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✗ Negative", table_body_style)], [Paragraph("CD5", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("Variable", table_body_style), Paragraph("✗ Negative", table_body_style)], [Paragraph("CD8", table_body_style), Paragraph("Variable", table_body_style), Paragraph("Variable", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("Variable", table_body_style)], [Paragraph("CD16", table_body_style), Paragraph("✗ NEGATIVE", S("n2",fontName="Helvetica-Bold",fontSize=8.5,textColor=ACCENT,leading=11)), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("Variable", table_body_style)], [Paragraph("CD56 ★", table_body_style), Paragraph("✓ POSITIVE", S("p2",fontName="Helvetica-Bold",fontSize=8.5,textColor=colors.HexColor("#1A7A1A"),leading=11)), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style)], [Paragraph("CD57", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("Variable", table_body_style)], [Paragraph("TIA-1 / Granzyme B / Perforin", table_body_style), Paragraph("✓ Positive (cytotoxic granules)", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style)], [Paragraph("EBV (EBER-ISH)", table_body_style), Paragraph("✓✓ ALWAYS+", S("p3",fontName="Helvetica-Bold",fontSize=8.5,textColor=colors.HexColor("#1A7A1A"),leading=11)), Paragraph("Usually+", table_body_style), Paragraph("✗ Negative", table_body_style), Paragraph("✓ Positive", table_body_style)], [Paragraph("TCR gene rearrangement", table_body_style), Paragraph("Germline (no rearrangement)", table_body_style), Paragraph("Germline", table_body_style), Paragraph("Germline", table_body_style), Paragraph("Germline", table_body_style)], [Paragraph("CD43 / CD45RO / HLA-DR", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("✓ Positive", table_body_style), Paragraph("Variable", table_body_style), Paragraph("Variable", table_body_style)], ] col_widths = [4.5*cm, 3.7*cm, 3*cm, 3*cm, 2.8*cm] cd_tbl = Table(cd_data, colWidths=col_widths) cd_tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,0), DARK_BLUE), ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, LIGHT_GREY]), ("GRID", (0,0), (-1,-1), 0.5, MID_GREY), ("TOPPADDING", (0,0), (-1,-1), 4), ("BOTTOMPADDING", (0,0), (-1,-1), 4), ("LEFTPADDING", (0,0), (-1,-1), 5), ("VALIGN", (0,0), (-1,-1), "MIDDLE"), # highlight CD56 row ("BACKGROUND", (0,8), (-1,8), colors.HexColor("#FFF3CD")), # highlight EBER row ("BACKGROUND", (0,11), (-1,11), colors.HexColor("#E8F8E8")), ])) story.append(cd_tbl) story.append(sp(5)) story.append(note_box( "★ CD56 is the hallmark NK cell marker but is NOT lineage-specific. " "ENKTL classic phenotype: CD2+, surface CD3−, cytoplasmic CD3ε+, CD56+, CD16−, EBER+. " "Absence of TCR gene rearrangement confirms NK cell (not T-cell) origin." )) story.append(sp(10)) # ── GENETICS ───────────────────────────────────────────────────────────── story.append(section_header("GENETICS & MOLECULAR PATHOLOGY")) story.append(sp(5)) story.append(Paragraph("Extranodal NK/T-cell Lymphoma (ENKTL)", body_bold)) gen_items = [ "No specific cytogenetic abnormality; del(6)(q21;q25) or i(6p10) described occasionally", "TCR genes in germline configuration (no rearrangement) — confirms NK lineage", "Recurrent mutations: JAK/STAT pathway (STAT3, STAT5B), epigenetic regulators (TET2, ARID1A), TP53", "PD-L1 / PD-L2 amplification and 3'-UTR rearrangements of PD-L1 gene → immune evasion (important therapeutic target)", "All tumor cells contain monoclonal EBV episomes — proves clonal origin from single infected cell", "EBV latency pattern: Type II (EBNA1, LMP1, LMP2A expressed; EBER always +)", ] for item in gen_items: story.append(Paragraph(f"• {item}", bullet_style)) story.append(sp(5)) story.append(Paragraph("Aggressive NK-cell Leukaemia (ANKL)", body_bold)) ankl_items = [ "Mutations in JAK/STAT and RAS/MAPK signaling pathways", "Epigenetic modifier mutations: TET2, CREBBP, KMT2D", "Immune checkpoint molecule alterations: CD274 (PD-L1), PDCD1LG2 (PD-L2)", "UV-related mutational signature described in some cases", ] for item in ankl_items: story.append(Paragraph(f"• {item}", bullet_style)) story.append(sp(10)) # ── PROGNOSIS ───────────────────────────────────────────────────────────── story.append(section_header("PROGNOSIS")) story.append(sp(5)) prog_data = [ [Paragraph("Entity", table_head_style), Paragraph("Prognosis", table_head_style), Paragraph("5-Year OS", table_head_style), Paragraph("Key Prognostic Points", table_head_style)], [Paragraph("ENKTL — Stage I/II (Localised)", table_body_style), Paragraph("Intermediate", S("pg",fontName="Helvetica-Bold",fontSize=8.5,textColor=colors.HexColor("#1A7A1A"),leading=11)), Paragraph("~50–70%", table_body_style), Paragraph("Responds well to CCRT (concurrent chemoradiotherapy) + L-asparaginase-based regimens (SMILE protocol)", table_body_style)], [Paragraph("ENKTL — Stage III/IV (Advanced)", table_body_style), Paragraph("Poor", S("pg2",fontName="Helvetica-Bold",fontSize=8.5,textColor=ACCENT,leading=11)), Paragraph("~20–30%", table_body_style), Paragraph("Chemotherapy-resistant (P-glycoprotein over-expression). HSCT and PD-1 inhibitors (pembrolizumab/sintilimab) used for R/R disease.", table_body_style)], [Paragraph("Aggressive NK-cell Leukaemia (ANKL)", table_body_style), Paragraph("Very Poor", S("pg3",fontName="Helvetica-Bold",fontSize=8.5,textColor=ACCENT,leading=11)), Paragraph("<10%", table_body_style), Paragraph("Fulminant disease; median OS days–weeks. HLH, multi-organ failure. HSCT only potentially curative.", table_body_style)], [Paragraph("CLPD-NK", table_body_style), Paragraph("Good", S("pg4",fontName="Helvetica-Bold",fontSize=8.5,textColor=colors.HexColor("#1A7A1A"),leading=11)), Paragraph(">80%", table_body_style), Paragraph("Indolent course. Watch-and-wait approach. Cytopenias may need treatment.", table_body_style)], [Paragraph("HV-LPD", table_body_style), Paragraph("Variable → Poor", S("pg5",fontName="Helvetica-Bold",fontSize=8.5,textColor=colors.orange,leading=11)), Paragraph("Variable", table_body_style), Paragraph("May transform to overt ENKTL or systemic ANKL. Mosquito-bite allergy subtype has poor outlook.", table_body_style)], ] prog_tbl = Table(prog_data, colWidths=[4*cm, 2.5*cm, 2.2*cm, 8.3*cm]) prog_tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,0), DARK_BLUE), ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, LIGHT_GREY, WHITE, LIGHT_GREY, WHITE]), ("GRID", (0,0), (-1,-1), 0.5, MID_GREY), ("TOPPADDING", (0,0), (-1,-1), 5), ("BOTTOMPADDING", (0,0), (-1,-1), 5), ("LEFTPADDING", (0,0), (-1,-1), 5), ("VALIGN", (0,0), (-1,-1), "TOP"), ])) story.append(prog_tbl) story.append(sp(5)) story.append(Paragraph("Prognostic Scoring: The Korean Prognostic Index (KPI) and PINK-E score " "(Prognostic Index for Natural Killer/T-cell Lymphoma with EBV DNA) are validated tools.", body)) story.append(Paragraph( "PINK-E factors: age >60, Stage III/IV, distant lymph node involvement, non-nasal type, " "elevated EBV DNA. Each factor scores 1 point; score 3–5 = high-risk group.", bullet_style)) story.append(sp(5)) story.append(note_box( "⭐ KEY EXAM POINT — Treatment rationale: ENKTL is relatively RESISTANT to CHOP " "(P-glycoprotein-mediated MDR). L-asparaginase-based regimens (SMILE: Dex/Mtx/Ifos/L-aspa/Etop) and " "radiotherapy are the backbone of treatment. PD-1/PD-L1 checkpoint inhibitors are now standard " "for relapsed/refractory ENKTL (WHO-5 era)." )) story.append(sp(10)) # ── SUMMARY TABLE ──────────────────────────────────────────────────────── story.append(section_header("QUICK SUMMARY — COMPARISON TABLE")) story.append(sp(5)) sum_data = [ [Paragraph("Feature", table_head_style), Paragraph("ENKTL", table_head_style), Paragraph("ANKL", table_head_style), Paragraph("CLPD-NK", table_head_style)], [Paragraph("Origin", table_body_style), Paragraph("NK cell (rarely γδ T)", table_body_style), Paragraph("NK cell", table_body_style), Paragraph("NK cell", table_body_style)], [Paragraph("EBV", table_body_style), Paragraph("Always +", table_body_style), Paragraph("Usually +", table_body_style), Paragraph("Negative", table_body_style)], [Paragraph("Key site", table_body_style), Paragraph("Nasal cavity/extranodal", table_body_style), Paragraph("Blood/marrow/spleen", table_body_style), Paragraph("Blood", table_body_style)], [Paragraph("Angioinvasion", table_body_style), Paragraph("Hallmark ✓", table_body_style), Paragraph("Absent", table_body_style), Paragraph("Absent", table_body_style)], [Paragraph("CD56", table_body_style), Paragraph("+", table_body_style), Paragraph("+", table_body_style), Paragraph("+", table_body_style)], [Paragraph("CD16", table_body_style), Paragraph("−", table_body_style), Paragraph("+", table_body_style), Paragraph("+", table_body_style)], [Paragraph("TCR rearrangement", table_body_style), Paragraph("Germline", table_body_style), Paragraph("Germline", table_body_style), Paragraph("Germline", table_body_style)], [Paragraph("Prognosis", table_body_style), Paragraph("Poor (Stage III/IV)", table_body_style), Paragraph("Very poor (<10% OS)", table_body_style), Paragraph("Good (indolent)", table_body_style)], ] sum_tbl = Table(sum_data, colWidths=[4.25*cm, 4.25*cm, 4.25*cm, 4.25*cm]) sum_tbl.setStyle(TableStyle([ ("BACKGROUND", (0,0), (-1,0), DARK_BLUE), ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, LIGHT_GREY]*10), ("GRID", (0,0), (-1,-1), 0.5, MID_GREY), ("TOPPADDING", (0,0), (-1,-1), 5), ("BOTTOMPADDING", (0,0), (-1,-1), 5), ("LEFTPADDING", (0,0), (-1,-1), 6), ("VALIGN", (0,0), (-1,-1), "MIDDLE"), ])) story.append(sum_tbl) story.append(sp(12)) # ── FOOTER ──────────────────────────────────────────────────────────────── story.append(HRFlowable(width="100%", thickness=1, color=MED_BLUE)) story.append(sp(4)) story.append(Paragraph( "Sources: Robbins & Cotran Pathologic Basis of Disease (10th ed.) | Henry's Clinical Diagnosis & Management by Laboratory Methods | " "Andrews' Diseases of the Skin | WHO Classification of Haematolymphoid Tumours, 5th Edition (2022) | " "Nature Leukemia 2022 (WHO-HAEM5 classification paper) | PMC 2025 review — non-B lymphoid neoplasms", footer_style)) # ── BUILD ───────────────────────────────────────────────────────────────── doc.build(story) print("PDF created:", OUTPUT) PYEOF python3 /tmp/workspace/nk-cell-lymphoma/make_pdf.py

Running Command

ls -lh /tmp/workspace/nk-cell-lymphoma/NK_Cell_Lymphoma_10_Mark.pdf

Your exam-ready PDF is ready:

NK Cell Lymphoma 10 Mark

PDF Document · PDF

Here is what the PDF contains, structured as a full MD Pathology 10-mark answer:

What's inside the PDF

1. Introduction

Brief overview placing T/NK lymphomas in the context of NHLs, noting the 10-15% (West) vs 25-35% (Asia) incidence and generally worse prognosis.

2. WHO 5th Edition (2022) — Types

A full colour-coded table covering all 6 NK-cell neoplasm entities per WHO-5:

Extranodal NK/T-cell lymphoma (ENKTL) - "nasal type" qualifier officially removed
Aggressive NK-cell leukaemia (ANKL) - now includes intravascular NK/T-cell lymphoma (moved from WHO-4R)
CLPD-NK (indolent)
Indolent NK-cell lymphoproliferative disorder of GI tract (provisional)
EBV-positive nodal NK-cell lymphoma (new entity in WHO-5)
Hydroa vacciniforme lymphoproliferative disorder (HV-LPD)

3. Etiology

ENKTL: EBV (clonal episomes, Type II latency), mechanism of entry unclear because NK cells lack CD21
ANKL: EBV + JAK/STAT, RAS/MAPK mutations, PD-L1/L2 alterations
HV-LPD: EBV + UV exacerbation + mosquito bite hypersensitivity

4. Microscopy

ENKTL: Angioinvasion (hallmark), coagulative/ischemic necrosis, azurophilic granules, EBER+ on ISH
ANKL: Large granular lymphocytes in blood/marrow, hemophagocytosis (HLH)
HV-LPD: Dermal/subcutaneous angiocentric infiltrate, epidermotropism

5. CD Markers — Full Immunophenotype Table

14-row comparison table (ENKTL, ANKL, CLPD-NK, HV-LPD) covering CD2, surface CD3, cytoplasmic CD3ε, CD4, CD5, CD8, CD16, CD56, CD57, TIA-1/Granzyme B, EBER-ISH, TCR rearrangement, CD43/HLA-DR. Key points highlighted in colour.

6. Genetics

ENKTL: Germline TCR, del(6q), JAK/STAT/TP53 mutations, PD-L1 3'-UTR rearrangement (WHO-5 addition)
ANKL: TET2, CREBBP, KMT2D mutations

7. Prognosis

5-row table with 5-year OS estimates, treatment backbone (CCRT + SMILE protocol), and checkpoint inhibitor use for R/R disease. Includes PINK-E scoring.

8. Quick Summary Comparison Table

Side-by-side ENKTL vs ANKL vs CLPD-NK on all key features.

Sources: Robbins Pathology, Henry's Clinical Lab Methods, Andrews' Skin Diseases, WHO Blue Books 5th Ed. 2022, Nature Leukemia WHO-HAEM5 paper.

This is a shared conversation. Sign in to Orris to start your own chat.