Granular cell tumor coexisting with adenocarcinoma in the stomach: Report of a rare case.

Abstract Introduction and importance: Granular cell tumor (GCT) is a benign, mesenchymal tumor that originates from Schwann cells. Case presentation A 75-year-old Japanese woman was referred to our hospital due to epigastric discomfort. Upper gastrointestinal endoscopy revealed an ulcerated cancer lesion, approximately 1.2 cm in diameter, at the angle of the stomach in the posterior gastric wall and a yellowish submucosal tumor, 5 mm in diameter, near an anal ulcerated lesion. Based on these findings, the patient was scheduled for laparoscopic distal gastrectomy and lymph node dissection. The pathological diagnosis was a moderately differentiated tubular adenocarcinoma invading mucosal stroma without lymph node metastasis and GCT in the stomach. Tumor cells were positive for S-100 and were consistent with the characteristics of GCT. Clinical discussion To the best of our knowledge, this is an extremely rare case with reports of only 6 cases of such a combination, including our case. Conclusions We believe that the coexistence of a GCT and gastric cancer in our patient was accidental and that there was no relation between them.