Testicular cancer treatment and implant in a 39-year-old man. The cancer affected the left testicle (at right), which has been removed (an orchidectomy) and replaced with an implant. The cancer was a spermatocytic seminoma, a malignant tumour (cancer) of the testis (testicle). Although this is a rare cancer, it is the most common cancer in 15 to 35- year-old men. It arises from abnormal germ cells (precursors to sperm cells) in the seminiferous tubules. Surgical removal of the affected testis (orchidectomy) is followed by radiotherapy and chemotherapy if required. For a view of this patient's cancerous testicle before surgery, see image C047/8463.