Spontaneous regression of primary malignant lymphoma of the stomach in two nontreated Japanese

Two patients with primary malignant lymphoma underwent spontaneous regression. One was a 40-year-old woman with a large ulcerating tumor on the greater curvature of the gastric antrum. This tumor shrank spontaneously, leaving only a small shallow ulcer. The resected specimen showed a minute focus of malignant lymphoma in the ulcer base. The other was a 73-year-old man who had a tumor with central ulceration on the posterior wall of the gastric antrum. Endoscopic biopsy revealed a malignant lymphoma. This tumor disappeared 60 days later. The patient refused surgery and remains well with no evidence of recurrent disease at this writing, 44 months later. Although there have been several case reports of spontaneous regression, partial or complete, of gastric malignant lymphoma, our cases seem to be the ones best proven.