Hematopathology: Practice Question
Question
A 60 year old patient is preliminarily diagnosed with the blastoid variant of mantle cell lymphoma. Further studies result in a diagnosis of lymphoblastic lymphoma. Which of the following would support the diagnosis of lymphoblastic lymphoma?
Answer Choices
- TdT expression
- CCND1 mutation
- CD19, CD20, CD22, CD79a positivity
- CD5 expression
- Dimorphic leukemic lymphocytes
Show Answer and Explanations
TdT expression — Correct answer
Correct. Lymphoblastic lymphoma, is the lymphoma version of acute lymphoblastic leukemia (ALL). It is positive for TdT, and negative for BCL-1 and CD5, unlike the blastoid variant of mantle cell lymphoma. Both of these entities can be leukemic.
CCND1 mutation
Incorrect. The t(11;14) places IgH upstream from CCND1, which leads to increased cyclin D1 / BCL-1 expression in mantle cell lymphoma.
CD19, CD20, CD22, CD79a positivity
Incorrect. Both the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma express pan B cell markers.
CD5 expression
Incorrect. Mantle cell lymphoma is positive for CD5 and BCL-1, as well as FMC7. Lymphoblastic lymphoma is positive for TdT.
Dimorphic leukemic lymphocytes
Incorrect. If leukemic, the blastoid variant of mantle cell lymphoma usually shows a dimorphic population of lymphocytes with mature and blast forms.
Summary
Summary: For distinguishing the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma: blastoid MCL is CD5 and BCL-1 positive, lymphoblastic lymphoma is TdT positive.Free account required. No subscription needed.