Differentiated intramucosal gastric carcinoma without ulceration showing extensive lymph node metastasis

Early gastric cancer is defined as gastric cancer confined to the mucosa or submucosa. For the majority of early gastric cancers without nodal involvement, endoscopic mucosal removal (EMR) is safer and more cost-effective than are other treatment methods. Here we report a rare case of differentiated mucosal carcinoma with extensive lymphovascular invasion and lymph node metastasis. Endoscopy showed a 5.5 cm non-ulcerated slightly elevated and depressed lesion without indication of submucosal involvement. Although the tumor met the extended criteria for EMR, D2 gastrectomy was performed. The resected specimen showed a 5.5 cm intramucosal carcinoma with extensive lymphovascular invasion of the submucosa, and metastasis to two perigastric nodes, indicating that metastasis can occur in patients with non-ulcerated differentiated mucosal tumors. Although these tumors are extremely rare, the risks and limitations of EMR should be fully considered in choosing an optimal surgical procedure.