What types of testicular cancer may occur?
95% of testicular cancers are secondary to germ cell tumors.
• Forty percent to 50% of germ cell tumors are seminomas (the most common pure histologic subtype). These occur in a slightly older age group (average age of 40), are radiosensitive, and are associated with a better prognosis. Serum alpha feto-protein (AFP) levels are not elevated. Treatment generally involves radical orchiectomy, sometimes along with adjuvant radiation therapy or chemotherapy.
• The remainder of germ cell tumors are nonseminomatous tumors, which include embryonal cell tumor, choriocarcinoma, yolk sac tumor, teratoma, and mixed subtypes. The mixed subtype is the most common histologic subtype of germ cell tumor overall and contains elements of multiple subtypes of germ cell tumor, including nonseminomatous tumors and seminoma. Nonseminomatous tumors occur in a slightly younger age group (average age of 30), are more aggressive in behavior, are less radiosensitive, and are associated with a worse prognosis. Serum AFP levels may be elevated, which is indicative of the presence of a nonseminomatous tumor. Treatment generally involves radical orchiectomy, sometimes with retroperitoneal lymph node dissection or chemotherapy.
The other 5% of testicular cancers are secondary to non–germ cell tumors, including sex cord stromal tumors (which are benign in 90%), gonadoblastoma, lymphoma, and metastatic disease to the testicle.