A CASE OF COLONIC METASTASIS OF GASTRIC CANCER DIFFERENTIATED FROM PRIMARY COLONIC CANCER WITH DIFFICULTY

Abstract

A 68-year-old woman was admitted to the hospital for the purpose of surgery after diagnosed as having gastric cancer (Borr 3). Colonofiberscopy performed for perioperative screening disclosed IIc type early cancer of the ascending colon. We diagnosed the case as synchronous double cancer involving the stomach and colon and performed a total gastrectomy (D2) and an ileocecal excision (D2). Histopathologically the colonic lesion was poorly differentiated adenocarcinoma (por2) associated with the same prominent fibrosis of the stroma as the gastric cancer had; it mainly situated in the submucosa and diffusely extended to the proper muscle layer. Accordingly gastric cancer with synchronous metastasis to the colon was diagnosed.
It is very rare that IIc type metastasis of gastric cancer is found in the ascending colon in which both the primary and metastatic lesions are simultaneously detected and successfully resected. Although preoperative examination of the colonic lesion revealed the same poorly differentiated adenocarcinoma as gastric cancer, we could not diagnose it as colonic metastasis before surgery and had a great difficulty in differentiation from primary colonic cancer. The reasons were because the colonic lesion had not diffuse invasive type in morphology which is characteristic of metastatic colorectal cancer, and it situated in the uncommon site for metastasis from gastric cancer.