In this study, Carr et al have made a small but significant contribution to the literature of diseases of the spleen and their surgical management. Over a 7½ year period, 86 consecutive patients with symptomatic splenomegaly were referred to the busy general surgical service of a large urban medical center. Of these patients, 18 (21%), or roughly 2 patients per year, had splenomegaly of unknown etiology, and they are the subject of this review. Two thirds of these patients had palpable spleens. All 18 patients had negative preoperative evaluations, including computed tomography or magnetic resonance imaging, bone marrow biopsies, and serum testing, and all were treated by open splenectomy. There were no operative deaths and minimal (22%) morbidity. The final pathological diagnoses in the 18 patients included: sarcoidosis (n = 4), benign hypersplenism (n = 6), Castleman disease (n = 1), and lymphoma (n = 7, 40%). The lymphomas diagnosed in these patients were the marginal zone variant in 5 patients and B-cell lymphoma in 2, both of whom had disseminated disease discovered at laparotomy. Four of the 5 marginal zone lymphoma patients were free of disease without additional treatment with a mean follow-up of 20 months.