Testicular cancer occurs when malignant cells form in the tissues of one or, less commonly, both testicles. It affects approximately one in 250 males at some point in their lifetimes. In the United States, the American Cancer Society estimates approximately 9,760 new cases of testicular cancer and around 500 deaths from the disease in 2024.

Since testicular cancer is typically treatable, the lifetime risk of a man dying from it is very low, roughly one in 5,000. Seminomas Nonseminomas Embryonal carcinoma: This nonseminoma grows quickly and can spread beyond the testicle. Under a microscope, these tumors resemble very early embryos, hence their name.

Yolk sac carcinoma: This type is rare in adults but the most common testicular cancer in children and babies. It generally responds well to treatment in children. Choriocarcinoma: This is a rare and aggressive testicular cancer that can rapidly spread to distant organs such as the lungs, bones, and brain.

It is often part of a mixed germ cell tumor. Teratoma: Teratoma contains tissue resembling all three layers of a developing embryo (endoderm, mesoderm, and ectoderm). Pure teratomas are rare and more commonly found as part of a mixed germ cell tumor.

Mixed Germ Cell Tumors Symptoms Swelling, a lump, hardening, or fluid accumulation in the testicles: Most testicular cancers consist of a painless mass in the testicle, typically palpable and several centimeters in size. Some do cause pain, however. Small, nonpalpable, asymptomatic m.