Introduction: Apocrine hidrocystoma (AH) is a rare, benign cystic tumour of apocrine glands, typically occurring in adults between 30 and 70 years of age without gender predilection. It most frequently affects the head and neck region, while genital localization, particularly in the scrotum, is exceedingly uncommon. To the best of our knowledge, this is the first reported case of giant scrotal apocrine hidrocystoma in an adult patient.
Case presentation: A 65-year-old male presented with a painless, translucent cystic nodule in the scrotal region gradually enlarging over several months. The lesion measured 45x30x25 mm and was surgically excised. Histopathological examination revealed a well-circumscribed, unencapsulated cystic lesion within the dermis, lined by two cell layers: an inner layer of apocrine cells exhibiting decapitation-type secretion and an outer myoepithelial layer. Immunohistochemical staining demonstrated AE1/AE3 positivity in luminal cells, and p63 expression in myoepithelial cells, confirming the diagnosis of AH.
Conclusion: Apocrine hydrocystoma of the scrotum is an extremely rare benign lesion and therefore represents a diagnostic challenge. Awareness of this entity is essential to avoid misdiagnosis with other cystic or adnexal lesions.