[Collision tumor of the stomach].

In a gastric neoplasm, malignant lymphoma is a relatively rare disease and a malignant lymphoma complicated by a carcinoma is very rarely found in the same stomach. As far as we could determine in a search of the literature, the coexistence of a gastric cancer and a malignant lymphoma was found in only 30 cases including our case and collision was seen in 10 of these. Our report concerns a recent case of malignant gastric lymphoma colliding with II c early gastric cancer, and is followed by a discussion. The patient, a man of 68, had complained of epigastralgia. The case was diagnosed as a gastric malignant lymphoma after an upper gastrointestinal roentgenogram and endoscopy. A biopsy revealed a torous malignant lymphoma (diffuse medium-sized cell type) and an II c early gastric cancer (tub 2) and suggested the collision between them.