265. Hodgkin's Disease; T Cell Disorders

Question 1

What are the 4 markers of normal mature T Cells?

Answer 1

CD 2, 3, 5, 7 (CD3 most important)

Question 2

Peripheral T Cell/NK Cell Lymphoma (GENERAL)

• epi
• tumor behavior

Answer 2

More common in ASIA

Usually AGGRESSIVE

Question 3

Adult T Cell Leukemia/Lymphoma (ATLL)

• etiology
• epi, demo
• CP
• prognosis
• morph (blood smear)
• cell of origin
• marker

Answer 3

E: HTLV-1 (Human T-cell Lymphoma Virus)
Epi: Japan, Caribbean, Central Africa
Demo: Adults only (avg 58yo) - exposed to virus early in life
CP: VaRiEs - leukemic, lymphomatous, smoldering
Prognosis: AGGRESSIVE, POOR (<10% survive 5 years)
Morph: lymphocytes with FLOWER-SHAPED NUCLEI
Cell of origin: CD4+ T Cell
Marker: loss of CD7

Question 4

Anaplastic Large Cell Lymphoma (ALCL)

• epi (2 subtypes)
• genetics
• prognosis (2 subtypes)
• morph (blood smear)
• marker

Answer 4

Epi: ALK+ ALCL more common in PEDIATRICS; ALK- ALCL more common in ELDERLY
Gene: ALK+ ALCL has t(2;5) or other translocation (ALK on Ch2)
Prognosis: ALK+ is FAVORABLE, ALK- is POOR
Morph: HALLMARK CELLS (large cells, horseshoe nuclei)
IHC: CD30+ (all types), ALK+ (only subtype)

Question 5

Extranodal NK/T Cell Lymphoma, Nasal Type

• etiology
• site of involvement
• prognosis
• markers

Answer 5

MOST ARE NK
Eti: EBV+
Sites: nasal cavity most common (can occur elsewhere)
Prognosis: POOR
IHC: NK phenotype (surface CD3-, cytoplasmic CD3+, CD56+, cytotoxic molecules+), EBV+
- NK cells therefore are stain CD3+ but flow cytometry CD3-!!!

Question 6

Mycosis Fungoides and Sezary Syndrome

• epi
• morph (blood smear)
• cell of origin
• marker
• prognosis
• triad of Sezary Syndrome

Answer 6

MF

• epi: most common primary cutaneous T Cell Lymphoma
• morph: CEREBRIFORM nuclei
• cell: CD4+ T cells
• IHC: CD7-
• Prognosis: INDOLENT

Sezary

• Erythroderma
• Generalized Lymphadenopathy
• Peripheral blood with CERIBRIFORM (convoluted) nuclei (Sezary cells - neoplastic)

Question 7

Hodgkin Lymphoma

• two major WHO categories of HL
• features/prognosis of first category
• features of second category (demo, markers, morph)
• most common subtype of second category (CP)

Answer 7

1. Nodular Lymphocyte Predominant HL (5% pts)
   - B Cell Neoplasm
   - GOOD prognosis
2. Classical HL (95% pts)
   - demo: BIMODAL age (younger and older adults)
   - markers: CD3-, CD20- (lose B cell), CD30+, CD15+ (KEY), PAX5+ (retains B cell transcription factor)
   - morph: REED-STERNBERG CELLS (large cell, bilobed nuclei, prominent nucleoli)

Nodular Sclerosis Classical HL
- 80% involve mediastinum