A 50–year–old Asian woman presented with 4 days of abdominal discomfort and progressive distention. She had no significant past medical history and did not consume alcohol. Her physical examination was remarkable for normal vital signs and a distended, non–tender abdomen with a fluid wave but without hepatosplenomegaly. Complete blood count and liver tests were normal. Abdominal ultrasound revealed ascites and an echogenic liver consistent with hepatic steatosis or cirrhosis, which was initially suspected. Viral hepatitis studies, human immunodeficiency virus antibody, ceruloplasmin, anti–mitochondrial antibody, alpha–1 antitrypsin, anti–smith antibody and antinuclear antibodies were negative. CA–125 was markedly elevated at 301 U/ml (normal < 22). Transvaginal ultrasonography revealed normal ovaries. Ascitic fluid examination revealed 42,900 total nucleated cells/cu mm of which 88% were mononuclear cells, 5% neutrophils and 7% lymphocytes. Further analysis showed abnormal B–cells expressing CD 19, CD 20, CD 10, FMC 7, and CD 45; FISH analysis showed MYC/IGH fusion associated with translocation of t(8;14)(q24;q32) characteristic of Burkitt’s lymphoma. Her serum LDH was 910 U/L (normal 82–310). Serum uric acid was normal. Computerized tomographic scanning failed to reveal hepatic or pulmonary involvement. Bone marrow biopsy and lumbar puncture were both negative for Burkitt’s involvement. She was treated with cyclophosphamide, vincristine, doxorubicin dexamethaosone, rituximab and methotrexate.
This woman presented with malignant ascites, the most common cause of which is ovarian cancer. This was initially assumed to be the diagnosis because of her elevated CA–125. The correct diagnosis was established by careful pathologic evaluation of ascitic fluid, showing monomorphic medium sized cells with basophilic cytoplasm and a high proliferation fraction with Ki–67 fraction approaching 100%. Translocation of the C–MYC gene on chromosome 8 is characteristic of Burkitt’s lymphoma. Burkitt’s lymphoma is rare, constituting less than 1% of B–cell lymphomas. It is more common in males and usually presents with masses and tumor lysis syndrome. Less commonly it may present with ascites. This form may have a rapidly progressive course with bowel obstruction and/or gastrointestinal bleeding. We are aware of only one previous case of Burkitt’s lymphoma presenting with ascites and an elevated CA–125.
This case illustrates a rare cause of malignant ascites, masquerading as ovarian cancer. Careful cytologic analysis of ascitic fluid cells led to the correct diagnosis.