PRIMARY MEDIASTINAL GERM-CELL TUMOR WITH INTRATUBULAR GERM-CELL NEOPLASIA OF THE TESTIS - FURTHER SUPPORT FOR GERM-CELL ORIGIN OF THESE TUMORS - A CASE-REPORT

BACKGROUND. The histogenesis of extragonadal germ cell rumors remains an enigma. The majority of patients with retroperitoneal tumors are ma le, and careful histologic evaluation reveals preinvasive intratubular germ cell neoplasia (ITGCN) or scars in the testis suggesting a so-ca lled ''burnt out'' germ cell tumor. However, in the testes of patients with primary mediastinal germ cell tumors, no ITGCN has been describe d in the literature to date. The authors report the first case of simu ltaneous germ cell neoplasia in the mediastinum and the testis, provid ing further insights into the biology and origin of these lesions. MET HODS. The authors report the pathologic features and cytogenetic findi ngs in an adult male with a mediastinal germ cell tumor and asymmetric testis. This patient died shortly after diagnosis. RESULTS. A locally invasive mediastinal nonseminomatous germ cell tumor was associated w ith ITGCN in one testis. Metastases were not present clinically or on autopsy during a detailed and systematic examination of retroperitonea l lymph nodes and other viscera, Neither an invasive germ cell tumor n or a scar was found in either testis (both testes were serially sectio ned and entirely examined histologically). CONCLUSIONS, The findings o f this study suggest that the mediastinal tumor is a primary neoplasm with concomitant in situ lesion in one testis, suggesting a more gener alized defect of germ cell and thus providing new information about th e unresolved issue of the histogenesis of extragonadal germ cell tumor s. This article presents a review of the literature concerning the iss ues highlighted by this case and discusses the hypotheses regarding th e development of extragonadal germ cell tumors. (C) 1997 American Canc er Society.