American Board of Pathology (ABPath) Practice Test

Seminoma is the most common type of testicular tumor, particularly in adults, representing about 30-40% of all testicular cancers. These tumors arise from the germ cells in the testes and are typically more prevalent in men aged 25 to 45. Seminomas are known for their favorable prognosis and are generally sensitive to radiation therapy and chemotherapy, which further highlights their importance in clinical practice.

The other types of tumors listed have distinct characteristics and occur with less frequency. While Sertoli cell tumors originate from Sertoli cells and are rare, yolk sac tumors, often seen in younger males, are considered a type of non-seminomatous germ cell tumor but also occur less frequently overall. Teratomas can develop in various age groups, but they are more common in prepubescent boys and do not account for the same prevalence as seminomas in the adult male population. Thus, the clear predominance of seminomas among testicular tumors establishes them as the most common type.