Splenic marginal zone lymphoma with or without villous lymphocytes

BACKGROUND Splenic marginal zone lymphoma (SMZL) is a well defined pathologic entity. However, questions regarding the bone marrow infiltration rate, the minimal diagnostic data set, and therapy remain unanswered. METHODS Clinical‐pathologic features and outcomes of 57 consecutive patients who had splenomegaly with no clinically significant lymphadenomegaly and who were diagnosed with SMZL with or without (±) villous lymphocytes (VL) were reviewed. RESULTS SMVL ± VL occurred mostly in elderly males (median age, 62 years ± 10 years; male‐to‐female ratio, (1.85). Anemia was recorded in 49% of patients, and 30% of patients had moderate thrombocytopenia. Leukocytosis and leukopenia were found in 33% and 14% of patients, respectively, and typical VL were found in 84% of patients. Serology for hepatitis C virus infection was positive in 16% of patients, and a small monoclonal component was detected in 36% of patients. The bone marrow was infiltrated with an intrasinusoidal component in all patients. Thirteen patients were monitored using a watch‐and‐see policy, and they remained alive 1–5 years after diagnosis. Overall, 21 patients (36%) underwent splenectomy; and, in all patients, the diagnosis of SMZL was confirmed histologically in the surgical specimens. Twenty‐five patients received single‐agent therapy, which included either alkylators or pentostatine, and they achieved an overall response rate (ORR) of 65% and 87%, respectively: Polychemotherapy was administered to 6 patients (ORR, 83%). The median survival for all patients in the series was not reached, and it is expected that 70% of patients will be alive at 5 years. CONCLUSIONS Up to 20% of patients who had SMZL ± VL could be monitored using a watch‐and‐wait policy. The bone marrow intrasinusoidal infiltration pattern may be a valuable diagnostic hallmark, thus obviating diagnostic splenectomy. The issues regarding prognostic stratification and the best therapeutic strategy need to be addressed in properly designed, prospective trials. Cancer 2004. © 2004 American Cancer Society. Splenic marginal zone lymphoma with or without villous lymphocytes is an indolent neoplasm, and up to 20% of patients require no therapy on diagnosis. The disease always involves bone marrow, although the infiltration may be very fine and exclusively intrasinusoidal. Bone marrow examination, coupled with the morphologic and immunophenotypic evaluation of peripheral blood, can lead to the correct diagnosis.