title: Age-related epididymis-like intratesticular structures: benign lesions of Wolffian origin that can be misdiagnosed as testicular tumors.
abstract: This study aims to characterize the epididymis-like intratesticular structures (ELITSs), a rare lesion found in elderly men. ELITSs were identified in 6 patients from a review of 1442 autopsies and 271 surgical specimens of adult men. Bilateral lesions were seen in 5 cases. The lesion was located in the proximity of the mediastinal rete testis (6 testes) and at the testicular periphery (4 testes), and at both central and peripheral locations in 1 case. The lesion is characterized by a pseudostratified cylindrical epithelium, with a robust pankeratin and 8, 18, and 19 keratin expression, focal vimentin expression, and apical CD 10 expression, similar to what is proper of the normal human epididymidis. The epithelial layer of ELITSs was surrounded by a thin layer of smooth-muscle cells. The adjacent testicular parenchyma was atrophied and the rete testis showed some associated degenerative lesions related to arteriosclerosis. The ELITSs are distinct from atrophic seminiferous tubules with a Sertoli cell-only pattern and from the benign glandular teratomatous component of an involution of a malignant testicular germ cell tumor, the so-called burn-out germ cell tumor. Clinical and histopathological data suggest that this lesion represents a late Wolffian differentiation similar to the initial segment of the epididymal duct, which represents an unusual manifestation of the aging process.
authors.affiliation: Departamento de Anatomia, Histologia y Neurociencia, Facultad de Medicina, Universidad Autonoma de Madrid, Calle Arzobispo Morcillo, 2. 28029, Madrid, Spain. mnistal.hulp@salud.madrid.org
authors.forename: Manuel
authors.initials: M
authors.lastname: Nistal
authors.forename: Miguel A
authors.initials: MA
authors.lastname: García-Cabezas
authors.forename: María C
authors.initials: MC
authors.lastname: Castello
authors.forename: María P
authors.initials: MP
authors.lastname: De Miguel
authors.forename: Javier
authors.initials: J
authors.lastname: Regadera
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D004822:Epididymis / Q000033:anatomy & histology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D013736:Testicular Neoplasms / Q000175:diagnosis* / Q000473:pathology; D013737:Testis / Q000033:anatomy & histology*; D014928:Wolffian Ducts / Q000473:pathology*