Müllerian serous cystadenoma of the scrotum following orchiopexy

Abstract

A 24-year-old man presented himself with a nodular lesion of about 1 cm diameter at the site of a previous orchiopexy associated with surgery for cryptorchism. Histopathology revealed the lesion to be adenomatous and confined to the scrotum. Histological and immunohistological features were not consistent neither with median raphe cysts or cutaneous adenomas nor with the intrascrotal adenomas of the rete testis, epididymis, nor with (malignant) mesotheliomas. However, the lesion did compare well with serous (papillary) cystadenomas of the testis or paratestis. These adenomas are thought to originate in remnants of the Müllerian system or of peritoneal lining altered by Müllerian metaplasia. This implies that the scrotal adenoma may have developed from an implant of such elements during orchiopexy 14 years ago. Complete excision of the lesion appears to be an adequate therapy.

Figure 1

Histological and immunohistochemical features of the scrotal serous cystadenoma at the side of an orchiopexy 14 years earlier. (a) Low magnification shows a tubulocystic tumor (between large arrowheads) surrounded by connective tissue and embedded in the dartos fascia (asterisks). Note its connection to the epidermis by a sinus (1) lined by cornifying stratified squamous epithelium and opening at the surface (arrow). (b) Detail of metaplastic noncornifying stratified squamous epithelium (2) passing into a single-layered columnar epithelium of the tubulocystic system (3) in the deepest part of the sinus. (c) Cystic papillary component. (d) Detail of a fibrous papilla covered by characteristic tall columnar epithelium with ciliated cells (small arrowheads). (e) Cytological and immunohistochemical characteristics discriminating the tumor from other scrotal and intrascrotal lesions. Vim: Vimentin; ER: Estrogen receptor; PR: Progesterone receptor; Calret: Calretinin; SMA: Smooth muscle actin.