Splenic Marginal Zone Lymphoma (SMZL): Clinical Course after Splenectomy. A Single Institution Experience

SMZL is an indolent B-cell malignancy accounting for 1–2% of chronic lymphoid leukemia found on bone marrow examination and up to 25% of low-grade B-cell neoplasms in splenectomy patients. Aggressive transformation of SMZL rarely occurs. It usually presents as an incidental finding or with symptoms of splenomegaly and anemia. There is still no reliable clinical or biological scoring system for prognostic stratification. We reviewed pathology reports of 41 splenectomized patients at HFHS from 1994 to 2007 and identified 14 patients with splenic marginal zone lymphoma (SMZL). The reasons for splenectomy were symptoms of splenomegaly in all 14 patients, anemia in 13 patients, thrombocytopenia in 12 patients, AIHA in 4 patients, splenic laceration in one patient. We report here the demographics, clinical course and pathology review of these patients. The median age of patients was 77.8 years. There were 7 male and 7 female patients. ECOG performance status was 0–1 in 12(86%), and 2 in 2(14%). Of the 14 patients, 8(57%) were at Ann Arbor stage IV, 1(7%) was at stage III, 4(29%) were at stage II, and 1(7%) at stage I. LDH was above normal in 9(64%) patients B-symptoms were observed in 1(7%).

Bone marrow involvement was documented in 8(57%) of the patients. Anemia in 13(93%), thrombocytopenia in 12(86%), AIHA in 4(29%). IPI score was 1–2 in 5(36%), and score 3–4 in 9(64%) of the patients. Median weight of the spleen was 1235 gm. Bone marrow cytogenetics were abnormal in 4(29%) cases. Following splenectomy, cytopenias resolved completely or partially (CR/PR) in 13(93%) patients. Bacterial infections were observed in 4(29%) patients and 2(14%) died of infectious complications. Progressive disease requiring additional systemic therapy was documented in 5(36%) patients. Total of 5(36%) patients died. One secondary to NSLC, 1(7%) of urothelial carcinoma, 1(7%) secondary to hypercalcemia, 2(14%) due to bacterial sepsis. Patients were followed up to 139 months (with median follow-up time of 42 months). The estimated median overall survival (OS) for this group was 116.5 months (9.7 years), the median progression-free survival (PFS) was 91 months (7.6 years). The Kaplan Meier method was used to calculate these estimates. A simple median was calculated for the sample median. In summary, we report the course of 14 patients with SMZL who underwent splenectomy for symptomatic disease. Only 5(36%) required systemic therapy following splenectomy. No death was attributed to progressive SMZL. Overall course was indolent even after splenectomy. Estimated OS was 116.5 months (9.7 years), PFS - 91 month (7.6 years).