Primary non-Hodgkin lymphoma of the spleen.

Primary splenic lymphoma is a relatively infrequent cause of splenomegaly, its reported incidence being less than 1%. Nonetheless, various series have reported on its occurrence and its unfavorable prognosis, but these series have reported data on heterogenous populations, including many patients with nodal or hepatic disease. We report on a series of nine patients with primary splenic lymphoma. None of these patients had biopsy-proven evidence of extrasplenic disease and were categorized as involving spleen only (stage 1) or spleen and splenic hilum (stage 2). In this series, classified by the recent N.C.I. working formulation, four patients had intermediate or high-grade histology and five patients had low-grade histology. There was no correlation between histological subtype and prognosis, nor could other factors be delineated to explain their favorable prognosis. The median survival in this group of patients was 7.48 years, and no evidence of relapse has been documented. The data suggest that primary splenic lymphoma, treated by splenectomy alone or combination therapy, may be potentially curative. Further studies should address the question of aggressive accurate staging in hopes of obtaining homogenous patient populations so that appropriate treatment in primary splenic lymphoma can be better defined.