Gastric Metastasis from Colorectal Cancer Mimicking a Submucosal Tumor

Signet-ring cell carcinoma, a colorectal cancer (CRC) subtype, sometimes shows metastases to uncommon metastatic sites. However, gastric metastasis is extremely rare. Here, we describe a case of gastric metastasis from colonic cancer. A 76-year-old woman presented with anemia. Colonoscopic biopsy revealed a CRC on the transverse colon showing a poorly differentiated adenocarcinoma with a partial component of the signet-ring carcinoma. Computed tomography revealed multiple subcutaneous nodules on her chest and back, and a tumor in the left lower lobe of her lung. Esophagogastroduodenoscopy showed a submucosal tumor-like lesion in the upper gastric body, and endoscopic biopsy revealed the poorly differentiated adenocarcinoma along with the partial component of the signet-ring carcinoma as well as the colonic, subcutaneous, and pulmonary lesion. The findings of endoscopic and microscopic examinations revealed gastric metastasis from CRC on the transverse colon. A systemic chemotherapy was given, and the biopsy conducted 1 year after the initial chemotherapy revealed no evidence of the residual tumor tissue in the gastric lesion. However, best supportive care was recommended depending on metastasis to the rectum. Our case suggests that gastric metastases from CRC should be considered in patients with lesions resembling a submucosal tumor accompanied by central depression and erosion.