Apocrine Hidrocystoma: A Rare Benign Cystic Skin Tumor at Uncommon Site.

Apocrine hidrocystoma (AH) is an uncommon benign cystic tumor, which arises from the apocrine secretory coil. The lesion is usually single and commonly seen over the face or scalp. It rarely involves the genitalia and if ever seen, then it occurs in foreskin followed by the shaft of the penis. AH commonly affects adults with equal gender incidence. Histopathological confirmation is done by the presence of cystic spaces in the dermis lined by bilaminar epithelium, outer myoepithelial cells and inner columnar, and eosinophilic cells with basally positioned nuclei, and often prominent apical snouts are also noted. It should be differentiated from other cystic lesions over the penile shaft. The treatment of choice is the complete excision. To date, only 13 cases of genital AH have been reported. Among that, very few cases have been reported over the penile shaft. Herein, we emphasize the importance of considering the differential diagnosis of the cystic lesion over the penile shaft.