[A Case of Synchronous Triple Cancer of the Sigmoid Colon, Breast, and Lung].

A 66-year-old woman visited a local hospital complaining of abdominal pain and fever. Blood tests and abdominal computed tomography revealed perforation of the gastrointestinal tract due to sigmoid colon cancer and generalized peritonitis. The patient was referred to our hospital for emergency surgery. Preoperative computed tomography revealed a mass shadow in the left mammary gland and right lung fields. Breast ultrasonography revealed an 8 mm irregular mass in the left mammary gland; the mass was diagnosed as primary breast cancer through a needle biopsy. The lung tumor was diagnosed as primary lung cancer by bronchoscopic biopsy. 18F-fluorodeoxyglucose positron emission tomography revealed aortic lymph node metastasis of sigmoid colon cancer, peritoneal dissemination, liver metastasis, and splenic metastasis. Based on these findings, we diagnosed the patient with highly advanced simultaneous triple carcinoma with distant metastasis. This report describes a rare case of simultaneous cancers of the sigmoid colon, breast, and lung.