3.27 STROM Hematologic MalignanciesII: T and NK cell Lymphomas

Question 1

T cell development and Markers

Answer 1

Question 2

NK Cell and gamma-delta dev and markers

Answer 2

Question 3

Angioimmunoblastic T-cell Lymphoma Presentation and Morphology

Answer 3

Clinical Presentation: rapidly progressive critical illness, diffuse lymphadenopathy, hepatosplenomegaly, skin rash, cold autoimmune hemolytic anemia, evidence of immunocompromise

• Normal Counterpart: Follicular T-helper cells (involved sites: lymph nodes, spleen, liver, BM and skin)
• Morphology: will see enlarged lymph node b/c of expanded paracortex
• Reactive will see expansion of small paracortical vessels and immunoblast, microscopic examination is not always helpful

Question 4

Angioimmunoblastic T-cell Lymphoma: Immunophenotyping

Answer 4

• CD3+, CD4+ and CD10+
• CD10: usally a marker of B-cells in germinal center, presence in paracortex on these T cells can lead toward diagnosis
• CD21: residual FDC network, should be absent if there is not a germinal center, but with this lymphoma they are present and staining for CD21+ can help diagnose

Picture: L-CD3 and R-CD10

Question 5

Angioimmunoblastic T-cell Lymphoma: Genetics and Clinical Course

Answer 5

• Complex Karyotypes: mult chromo loss/gain, mult deletions, no pattern has emerged
• Clinical Course: Aggressive, median survival >3yrs

Question 6

Periperipheral T-cell Lymphoma Not otherwise specified (NOS): Clincal presentation and features

Answer 6

~30% T cell lymphomas

• Clinical presentation: (1) Diffuse lymphadenopathy (2) B symptoms (fever, night sweats, weight loss) (3) paraneoplastic features (eosinophilia, pruritis, hemolytic anemia)
• Normal counter part: unclear

-Involved sites: any where, except usually NOT blood stream

Usual Themes: expanded paracortex, effacement of normal architecture

Variations: Distinct subsets of atypical cells or clusters of “epitheloid histocytes” usually near the cortex (paracortical, picture)

Question 7

Periperipheral T-cell Lymphoma Not otherwise specified (NOS): Immunophenotype and Clinical Course

Answer 7

Immunophenotype:

• expected; CD3, 5, 7, and 4 or 8/
• Usually see; loss of one or more of the above
• Variants: “double +” (CD4+, CD8+)

–Unexpected markers: CD20 (B-cell marker), CD56 (macrophage/monocyte marker), CD30 (R/S cell marker)

• Genetics: no pattern has emerged
• Clinical Course: aggressive 5 yr survival 20-30%