The gross appearance is heterogeneous, composed of solid, cartilaginous, and cystic areas. Hemorrhage and necrosis are common. They tend to be larger than other germ cell tumors. They may occur at any age. Testicular tumors tend to metastasize through the lymphatics, with para-aortic nodes the first to be involved.
Hematogenous spread is often to the lungs and liver.
The histology of the metastasis may be different than that of the primary tumor. Seminomas are monomorphic and necrosis is uncommon. They tend to remain localized to the testis for a longer period of time and thus present at an earlier clinical stage. Nonseminomatous germ cell tumors, including mature and immature teratomas, have a varigated appearance and often display hemorrhage and necrosis. These tumors are biologically more aggressive and radioresistant.