Introduction Testicular tumors can be of germ cell or non-germ cell origin germ cell origin are the majority (95%) and are more commonly malignant non-germ cell origin usually benign Epidemiology incidence most common cancer in men between 15-35 years risk factors cryptorchidism Klinefelter syndrome testicular feminization Classification Germ cell types seminoma malignant most common testicular tumor mostly affecting males 15-35 years commonly metastasizes to para-aortic lymph nodes before hematogenous spread embryonal carcinoma malignant commonly metastasizes early yolk sac (endodermal sinus) tumor seen in children < 4 years choriocarcinoma malignant teratoma mature teratoma in males is most often malignant unlike females Non-germ cell types Leydig cell (sex-cord stromal) Sertoli cell (sex-cord stromal) Testicular lymphoma most common testicular cancer in older men involves both testes Presentation Symptoms painless unilateral enlargement of testes seminoma homogenous testicular enlargement embryonal carcinoma painful choriocarcinoma gynecomastia due to hCG production which is an LH analogue Leydig cell usually androgen producing gynecomastia in men precocious puberty in boys Physical exam solid mass of the testes is always cancer Evaluation Histology seminoma large cells in lobules with watery cytoplasm "fried egg" analogous to dysgerminoma of the ovary embryonal carcinoma glandular/papillary yolk sac (endodermal sinus) tumor yellow, mucinous Schiller-Duval bodies resemble primitive glomeruli choriocarcinoma disordered syncytiotrophoblastic and cytotrophoblastic elements teratoma contain three tissue types leydig cell contains Reinke crystals golden brown color Serology LDH non-specific specific tumor markers embryonal carcinoma ↑ AFP and hCG yolk sac (endodermal sinus) tumor ↑ AFP choriocarcinoma ↑ hCG Treatment Pharmacologic & radiation radiation therapy indications seminoma is radiosensitive Surgical orchiectomy Prognosis Seminoma late metastasis and excellent prognosis Embryonal worse prognosis than seminoma Choriocarcinoma worst prognosis in contrast to good prognosis in females metastasizes to lungs