Serum tumor markers and testicular germ cell tumors: a primer for radiologists.

Serum tumor markers (STMs) play a critical role in the diagnosis, staging and follow-up of both seminomatous and nonseminomatous testicular germ cell neoplasms. Levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (HCG), and lactate dehydrogenase (LDH), especially those measured after orchiectomy, also have implications for patient prognosis. Given that testicular germ cell tumors represent the most common solid tumor in men aged 20-34, radiologists must have familiarity with the clinical utilization and implications of these STMs. This article will review the classical patterns of STM elevation most commonly seen in pure seminomatous and nonseminomatous germ cell tumors while also providing case-based examples highlighting the importance of STM correlation with imaging. The role of STMs in clinical staging and disease surveillance will also be discussed.