Splenic lymphoma with circulating villous lymphocytes. Report of a case with immunologic and ultrastructural studies.

A case of splenic lymphoma with circulating villous lymphocytes is reported. Short surface cellular expansions were observed on blood and marrow films and by transmission electron microscopy. The immunophenotype was that of mature B cells without CD5, CD10, CD11c, or CD25 expression or tartrate-resistant acid phosphatase. Despite a basophilic plasmacytoid-like cytoplasm, this case of splenic lymphoma with circulating villous lymphocytes differed from splenic immunocytoma in that immunofluorescence and ultrastructure suggested that the neoplastic cells did not possess high levels of intracytoplasmic immunoglobulin. Treatment of cytopenia was best achieved by splenectomy and the total follow-up thus far (30 months) seems to indicate a case of low-grade malignant lymphoma.