Two cases of advanced gastric carcinoma mimicking a malignant gastrointestinal stromal tumor

Gastric cancer that mimics a submucosal tumor is rare. This rarity and the normal mucosa covering the protuberant tumor make it difficult to diagnosis with endoscopy. We report two cases of advanced gastric cancer that mimicked malignant gastrointestinal stromal tumors preoperatively. In both cases, the possibility of cancer was not completely ruled out. In the first case, a large tumor was suspected to be cancerous during surgery. Therefore, total gastrectomy with lymph node dissection was performed. In the second case, the first gross endoscopic finding was of a Borrmann type II advanced gastric cancer-like protruding mass with two ulcerous lesions invading the anterior wall of the body. Therefore, subtotal gastrectomy with lymph node dissection was performed. Consequently, delayed treatment of cancer was avoided in both cases. If differential diagnosis between malignant gastrointestinal stromal tumor and cancer is uncertain, a surgical approach should be carefully considered due to the possible risk of adenocarcinoma.