A 48 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 2.7 X 1091 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 CD 19, CD5, CD20 and CD23 and were negative for CD 79 B and FMC-7. The histopathological examination of the lymph node in this patient will most likely exhibit effacement of lymph node arachitecture by -
High-Yield Explanation
Ans is 'd' i.e., A diffuse proliferation of medium to large lymphoid cells with high mitotic rate o Lymphocytes postive for CD 19, CD20, CD23, CD5 suggest the diagnosis of chronic lymphocytic leukemia/small lymphcytic lymphoma. o In CLL/SLL larger lymphocytes show high mitotic activity and form proliferation centre. Chronic lymphocytic leukemia (CLL). small lymphocytic lymphoma (SLL). o CLL and SLL are identical neoplasms/arise due to an abnormal neoplastic proliferation of B cells. o CLL involves primarily bone marrow and blood, while SLL involves lymph nodes Morphology of CLL/SLL o The tumor cells of CLL are small B lymphocytes. o Leukemic cells have the morphological appearance of normal small to medium sized lymphocytes with clumped chromatin, inconspicuous nuclei and a small ring of cytoplasm. o The lymph node architecture is diffusely effaced by these tumor cells. o These cells are mixed with variable numbers of larger cells called prolymphocytes. o In many cases, prolymphyocytes gather together focally to form as proliferation centers, so called because they contain relatively large number of mitotic activity. o When present proliferation centers are pathognomonic for CLL/SLL. o In CLL, the peripheral blood contains increased numbers of small, round lymphocytes with scant frequently disrupted in the process of making smears, producing So called smudge cells.. Markers of CLL tumor cells o CLL is a tumor of mature B-cells, therefore it expresses the B-cell markers such as CD19, CD20 and surface IgM and IgD. o In addition CD23 and CD5 are also present (In contrast to mantle cell lymphoma which is positive for CD5 but negative for CD23).