TOPICS: Epidemiology, males 15-35 years, unilateral painless testicular mass, discomfort, heaviness, dull aching lower abdominal pain, transilluminated, cryptorchidism, klinefelter syndrome (47,XXY), bilateral scrotal ultrasound, biopsy contraindicated, radical inguinal orchiectomy, chemotherapy, radiotherapy, germ cell tumors, seminoma, female dysgerminoma, primordial germ cells, radiosensitive, beta hcg, non seminomas, hematogenous spread, not radiosensitive, yolk sac tumor, endodermal sinus tumor, schiller duval body, primitive glomeruli, afp, choriocarcinoma, trophoblastic tissue, hemorrhage, necrosis, hyperthyroidism, gynecomastia, teratoma, neural tissue, cartilage, muscle, embryonal carcinoma, glands, sex cord stromal tumors, leydig cell tumors, reinke crystals, gynecomastia, precocious puberty, sertoli cell tumor, cordlike structures, tubules, lymphoma, secondary tumor, bilateral, diffuse large B cell lymphoma