Abdominal Burkitt's lymphoma diagnosed by fine needle aspiration cytology--a case report.

A case of abdominal Burkitt's lymphoma diagnosed through aspiration cytology is described. This 9-year-old boy presented with abdominal pain and distention for three months accompanied by fever and night sweat during the last month. An abdominal sonography and CT scan showed hepatosplenomegaly and an intrahepatic mass with celiac lymph node enlargement, ascites, and pleural fluid. A peripheral blood smear showed a few blast cells. Aspiration of the abdominal mass revealed very cellular aspirates consisting of diffusely scattered small monotonous round cells. The cells had little cytoplasm, along with round nuclei that showed clear-cut nuclear membrane, coarse chromatin pattern, and multiple small prominent nucleoli. Differential diagnoses considered were small round cell sarcomas such as malignant lymphoma, neuroblastoma, Ewing's sarcoma, and rhabdomyosarcoma. Of these, malignant lymphoma of the small noncleaved cell type was most consistent with the results of several studies including immunohistochemical staining, peripheral blood smear, and bone marrow biopsy. The cells were positive for leukocyte common antigen (LCA) and showed finely vacuolated basophilic cytoplasm in both the peripheral blood smear and bone marrow biopsy, characteristic of Burkitt's lymphoma cells.