Cytologic diagnosis of peripheral T-cell lymphoma manifesting as ascites. A case report.

BACKGROUND

Patients with malignant lymphoma seldom present with effusions without a known history of malignancy. Because of this, initial diagnosis of malignant lymphoma by effusion cytology is uncommon, with few reported cases.

CASE: A 75-year-old male presented with fatigue, decreased appetite and progressively increasing abdominal girth over five weeks. Cytologic examination of ascitic fluid obtained by paracentesis revealed non-Hodgkin's lymphoma with a T-cell phenotype, confirmed by immunophenotypic and molecular studies. Approximately one week later, histologic examination of liver and bone marrow revealed involvement by lymphoma, demonstrating immunophenotypic and molecular profiles identical to those obtained from neoplastic lymphocytes recovered from the ascites fluid.

CONCLUSION

This case demonstrates a rare presentation of peripheral T-cell lymphoma, clinically manifesting as ascites. In cases such as ours, where the effusion consists predominantly of small to intermediate-sized lymphocytes, distinguishing lymphoma from reactive lymphocytosis may be difficult. This case not only demonstrates the value of effusion cytology for lymphoma diagnosis but also illustrates how the use of various immunophenotypic and molecular techniques may assist the pathologist in properly diagnosing these difficult cases.