A 68 year old woman was admitted with a history of weakness for two months. On examination, cervical lymph nodes were found enlarged and spleen was palpable 2 cm below the costal margin. Her hemoglobin was 10.5 g/dl, platelet count 27 x 109/L and total leukocyte count 40 x 109/L, which included 80 % mature lymphoid cells with coarse clumped chromatin. Bone marrow revealed a nodular lymphoid infiltrate. The peripheral blood lymphoid cells were positive for CD19, CD5, CD20 and CD23 and were negative for CD79B and FMC-7. The histopathological examination of the lymph node in this patient will most likely exhibit effacement of lymph node architecture by?

This is a case of elderly female with lymphadenopathy, splenomegaly and peripheral blood lymphoid cells were positive for CD19, CD5, CD20 and CD23 and negative for CD79B and FMC-7. This findings are consistent with a diagnosis of Chronic lymphocytic leukemia. In CLL, lymph node biopsy is suggestive of pseudofollicular pattern with proliferation centers. Remember that, CLL lymph nodes show a low mitotic rate. This rules out option D Option B suggests Hodgkin lymphoma Option C suggests Follicular Lymphoma Option D suggests a high grade NHL with high mitotic rate Small fraction of tumors transform to aggressive tumors resembling diffuse large B cell lymphoma (Richter transformation); after transformation occurs, the median survival is less than 1 year.