A case of gastric hamartomatous inverted polyp (submucosal tumor type) accompanied by gastric cancer

Endoscopic examination of a 39-year-old woman revealed a flat-elevated submucosal tumor (SMT) in the upper third area of the stomach and a IIc lesion in the anterior wall of the lower third of the stomach. Endoscopic ultrasonography findings suggested an aberrant pancreas. Both lesions were resected by distal gastrectomy. Histological examination of the SMT revealed the dilated glands with cyst formation and proliferation of smooth muscle bundles in the submucosal layer, and it was diagnosed as a gastric hamartomatous inverted polyp. The IIc lesion was a signet ring cell carcinoma. Cases of gastric hamartomatous inverted polyps coexistent with gastric cancer have been rarely reported in Japan.