Mature T Cell Neoplasms

Question 1

Describe the morphology of Peripheral T Cell Lymphoma

Answer 1

• Diffuse or paracortical effacement
• Pleomorphic Mixture of Small and Large sized Malignant Cells
• Prominent Vessels

Question 2

Immunophenotype of Peripheral T-Cell Lymphoma

Answer 2

Loss of T cell antigens (mature T cells have CD34 and TdT)

Question 3

What causes Anaplastic Large Cell Lymphoma?

Answer 3

Translocation involving ALK gene on 2p23

The ALK will behave like a tyrosine kinase

Question 4

Describe the morphology of anaplastic large cell lymphoma

Answer 4

Large anaplastic cells with horseshoe or wreath shaped nuclei; the neoplastic cells often congregate around venules and sinuses of the node

Question 5

Define Adult T-Cell Leukemia/Lymphoma

Answer 5

CD4+ T Cells infected with the retrovirus HTLV1

endemic in Caribbean, Japan and West Africa

Question 6

What are the clinical features of Adult T Cell Leukemia?

Answer 6

General adenopathy, skin lesions, lymphocytosis, hypercalcemia

Leukemia presentation = rapidly progressive
Skin Localized Presentation = less aggressive

Question 7

Describe the morphology and immunophenotype of Adult T Cell Leukemia/Lymphoma

Answer 7

Flower or cloverleaf shaped cells, immunophenotype is CD4 positive and CD7 negative; also HTLV1 +

Question 8

What are the clinical features of Mycosis fungoides and Sezary Syndrome?

Answer 8

MF- 3 stages (patch, plaque and tumor)

SS- generalized exfoliative erythroderma + leukemia, can spread to involve lymph nodes and bone marrow

Question 9

Morphology of Mycosis Fungoides/Sezary Syndrome

Answer 9

Skin- infiltration of the epidermis and upper dermis
Neoplastic Cells- cerebriform nuclear contours
Sezary Cell- neoplastic cell in blood

Question 10

What mutation occurs in 30% of Large Granular Lymphocytic Leukemias?

Answer 10

STAT3 mutations

Question 11

What type of cells are involved in Large Granular Lymphocytic Leukemia?

Answer 11

T and NK Cells

Question 12

What are the clinical features of Large Granular Lymphocytic Leukemia?

Answer 12

1. Neutropenia (w/ decrease in myeloid maturation)
2. Anemia
3. Rheumatologic Disease
   Felty Syndrome

Question 13

What is Felty Syndrome?

Answer 13

Rheumatoid Arthritis + Splenomegaly + Neutropenia (may have LGL as a cause)

Question 14

What are the clinical features of Peripheral T Cell Lymphoma?

Answer 14

Generalized lymphadenopathy, eosinophilia, pruritis and weight loss

Equivalent of DLBCL but with worse prognosis