There are several types of cells found in the testicles, all of which can become cancerous. However, there are two main types of tumors that define most testicular cancers:

Seminoma– there are two subtypes of seminomas; Classical or typical seminomas usually occur in men aged 30-50. Spermatocyclic seminal segments are uncommon and develop more frequently in men over 55 years of age. However, both types of tumors can occur in all age groups.

Non-Seminoma– There are four main subtypes of non-seminoma or non-seminoma tumors: embryonic carcinoma, Yolk sac tumors, teratocarcinoma, and choriocarcinoma. These types of tumors generally occur during adolescence. They also tend to grow and spread faster than seminomas. Testicular cancer may involve one or both types of tumors.

Gonadal stromal tumors are a rare form of testicular cancer, accounting for about 5% of cases. In addition to the production of sperm for reproduction, male testicles or gonads are also a component of the endocrine system. Testicular stromal cells produce male sex hormones (androgens) such as testosterone. Most stromal tumors are benign, that is, tumoral plugins do not spread (metastasize) to other parts of the body. However, stromal tumors that sometimes spread do not respond to conventional treatments, such as chemotherapy or radiation.