[A Case of Primary Testicular Mucinous Carcinoma].

A 68-year-old man presented withleft testicular painless swelling. His carbohydrate antigen 19-9 and carcinoembryonic antigen levels were elevated but his germ cell tumor markers were not high. Magnetic resonance imaging showed multiloculated cystic lesions with solid components in his left testis. Abdominal and chest computed tomography revealed multiple lung metastases, peritoneal dissemination and multiple lymph node metastases. Left high orchiectomy was performed. Histopathological examination demonstrated testicular mucinous carcinoma withsimilarity to gastric cancer. Since no tumor was found by the endoscopy of the upper gastrointestinal and the lower digestive tract, we diagnosed the patient with primary testicular mucinous carcinoma. Standard chemotherapy for gastric cancer, which consisted of tegafur, gimeracil and oteracil (TS-1) and cisplatin was administered for 16 months, and there was no progression of the disease. He died from testicular mucinous cancer 30 months after the diagnosis. In the literature, only 4 cases of testicular mucinous carcinoma have been reported. TS-1 and cisplatin are useful chemotherapeutic options for testicular mucinous carcinoma withmetastasis.