Abstract
A 38-year-old man was admitted to a nearby clinic for abdominal pain and abnormal stools. A tumor was seen involving the entire circumference of the sigmoid colon on lower gastrointestinal endoscopy, and the biopsy showed group 5 (adenocarcinoma). Abdominal computed tomography showed liver and adrenal gland lesions, leading to a diagnosis of multiple organ metastases of colon adenocarcinoma. Surgery was performed because of the abdominal pain caused by the stenosis. Peritoneal dissemination was found during surgery. On pathological examination, the diagnosis was primary choriocarcinoma of the colon. The patient then underwent chemotherapy based on the colon adenocarcinoma (mFOLFOX6+ bevacizumab), but liver function deteriorated rapidly, and he died of hepatic failure 59 days after surgery.
Primary gastrointestinal choriocarcinoma is rare ; only 10 cases of primary colonic choriocarcinoma have been reported worldwide. Since metastases are very likely to be present at the initial visit, as in the present case, these patients' prognosis is very poor.
