[A Case of Subcutaneous Scrotal Metastasis from Primary Gastric Cancer]

Metastases to the subcutaneous scrotum are extremely rare. Here, we report a 78-year-old man who presented with pain to the scrotum and inguinal area. Two years ago, he underwent total gastrectomy for gastric cancer. The pain was attributed to increased scrotal wall thickness. Incisional biopsy of the thickened scrotal wall revealed diffused infiltration of the subcutaneous tissue by islands of scirrhous type malignant cells. Moreover, immunohistochemical studies showed that the tumor cells were positive for CK7, CK20, and CDX-2. These features suggested a metastatic adenocarcinoma of upper gastrointestinal origin. Although there were no visceral metastases, the tumor cells were too widely spread to be dissected curatively. Palliative chemotherapy with tegafur, gimeracil, and oteracil (S-1) was restarted, and local pain was subsequently ameliorated. Since scrotal metastasis is unlikely to occur it is difficult to diagnose. Therefore, in patients with groin discomfort or swelling and a history of gastric cancer, metastatic adenocarcinoma should be included in the differential diagnosis for early detection of a tumor.