Spontaneous regression of malignant lymphoma of the stomach.

We report a case of complete and spontaneous regression of malignant lymphoma of the stomach. A submucosal tumor with central ulceration was detected on the greater curvature of the stomach in a 63-year-old woman. The tumor was diagnosed histopathologically as a diffuse large B-cell lymphoma (REAL classification). The tumor disappeared 18 days later without chemotherapy. Examination at that stage showed Helicobacter pylori (H. pylori), which was later treated with antibiotics. There was no evidence of recurrence of the malignant lymphoma at the last follow-up conducted at the time of preparation of this report, 13 months after the initial diagnosis. Spontaneous regression of an intermediate and high-grade non-Hodgkin's lymphoma is uncommon. We discuss the possible role of H. pylori in the regression of gastric malignant lymphomas.