Subcutaneous metastasis arising from gastric cancer: A case report.

A 59-year-old man was referred to the Kochi Medical School Hospital due to left shoulder pain. Physical examination revealed a nodular, painful mass lesion in the subcutaneous tissue of the right chest wall, with a diameter of ~2 cm. Esophagogastroduodenoscopy revealed a large ulcerated tumor in the lower gastric body near the lesser curvature, and biopsy specimens of the gastric and humeral lesions revealed poorly differentiated adenocarcinoma. Abdominal computed tomography revealed multiple low-density lesions in the liver and a well-defined, 2.2-cm mass in the subcutaneous tissue of the right chest wall. The diagnosis was advanced gastric cancer with metastases to the liver, bone and skin, and systemic chemotherapy with radiotherapy for the bone metastasis was recommended. The patient also underwent distal gastrectomy to control bleeding from the primary gastric cancer lesion due to unresolved anemia, not improving by blood transfusion, and a low hemoglobin level. The subcutaneous tumor in the right chest wall was resected at the same time, to alleviate the pain caused by the mass. Macroscopic examination of the resected specimen revealed a well-circumscribed, solid tumor, measuring 2.2×2.1 cm, with a firm consistency. Microscopic examination showed infiltration of poorly differentiated adenocarcinoma cells into the subcutaneous tissue. Subcutaneous metastasis from gastric cancer is a rare manifestation, with a reported incidence of 0.8-1.0%. Cutaneous metastasis of cancer generally appears late in the course of the disease. Surgical resection of metastatic skin tumors is occasionally undertaken as palliative treatment to improve the patient's quality of life by controlling severe symptoms, including pain and hemorrhage.