umls-concept:C0855197 | skos:definition | NCI: Cancer that forms in tissues of the testis (one of two egg-shaped glands inside the scrotum that make sperm and male hormones). Testicular cancer usually occurs in young or middle-aged men. Two main types of testicular cancer are seminomas (cancers that grow slowly and are sensitive to radiation therapy) and nonseminomas (different cell types that grow more quickly than seminomas).,NCI: A malignant tumor predominantly affecting young men and often associated with cryptorchidism. Seminoma is the most frequently seen malignant testicular germ cell tumor, followed by embryonal carcinoma and yolk sac tumor. -- 2004 | lld:umls |