Primary gastric non-Hodgkin's lymphoma: a clinicopathological study of 41 patients.

Pathological findings in 41 patients (male/female ratio: 1.3/1) with primary localized gastric non-Hodgkin's lymphoma (NHL) were retrospectively studied and correlated with survival. The median observation period after diagnosis was 32 (0-189) months. Nineteen patients were low-grade NHL, all but one B-cell lymphomas of the mucosa-associated lymphoid tissue (MALT) type. Twenty-two patients had primary (n = 7) or secondary (n = 15) high-grade lymphomas; Musshoff stage IE was found in 29 and IIE in 12 cases. The median age at diagnosis was 61 years (range, 26-88 years), and proliferation, measured by the number of mitosis and Ki-67 antigen positivity (MIB-1), was high or moderately high in 24 cases and low in 17 cases. Follicular lymphatic hyperplasia could be found in 25 of 34 evaluable cases, more often in low-grade than in high-grade NHL. Most of the patients were treated by resective surgery and additional ratio- or chemotherapy. Thirteen patients (31%) died (median survival: 10 months), 5 of them within 3 months after surgery owing to postoperative complications. Survival was superior, though not statistically significant, in low-grade lymphomas. Our retrospective analysis of heterogeneously treated gastric lymphomas reveals that gastric lymphomas, especially of the low-grade MALT type, often remain a localized disease with a good long-term prognosis. Our study confirms previous reports indicating that lymphomas of the MALT type represent a specific clinicopathological entity.