Acquired adenomatous hyperplasia of the rete testis: an immunohistochemical study of its pathogenesis

Adenomatous hyperplasia of the rete testis (AHRT) is an uncommon abnormality first described by Nistal and Paniagua in 1988. Congenital and acquired forms of AHRT are recognized. We present a case of AHRT in a patient who underwent bilateral orchiectomy for penile carcinoma; he had received chemotherapy for Hodgkin lymphoma 18 years prior. Proposed causes for this disorder include developmental, hormonal, and paracrine induction by adjacent testicular tumors and exposure to chemicals, based on clinical contexts but without experimental support. We performed immunohistochemical studies using markers of cell cycle (cyclin D1, p16), proliferation (Ki-67), apoptosis (bcl2), senescence (γ-H2AX), and androgen receptors to try to provide scientific support for or refute existing hypotheses. Our results indicate that, in this case of acquired AHRT after chemotherapy, the process is neither adenomatous nor hyperplastic but rather represents abnormal accumulation of rete testis cells with acquired senescence.