title: Bilateral testicular tumors of germ cell origin.
abstract: Four cases of primary testicular tumor of germ cell origin are reported. Three  cases were bilateral, while the remaining case involved a unilateral tumor in a non-twin brother of 1 patient with bilateral tumors. Because of the increased likelihood of a second primary tumor developing in a patient who has had a malignant germinal cell tumor and because the changes may be subtle, localized to the testis and occur after a tumor-free interval of many years, careful examination of the contralateral testis and long-term followup are indicated even when systemic chemotherapy for malignancy has been used. This is the seventh time familial occurrence of testis tumors in non-twin brothers has been reported but the first time that one of the brothers had bilateral tumors.
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D008297:Male; D013724:Teratoma / Q000453:epidemiology / Q000235:genetics; D013736:Testicular Neoplasms / Q000453:epidemiology / Q000235:genetics