Background: Adenomas in the anogenital region are uncommon and the origin of this kind of lesion has created confusion. In the past these lesions have been considered as ectopic breast tissues or as cutaneous apocrine glands. More recently they have been defined as mammary-type anogenital glands. Methods: This case reports an anogenital mass in a 47-year-old woman that was removed and subsequently studied through a pathological and immunostaining study. Results: Microscopic tissue sections showed a morphologic pattern similar to that of a mammary fibroadenomas, and immunostaining demonstrated the presence of oestrogen receptors and progesterone receptors. The definitive diagnosis was an apocrine adenoma tubulo-papillary without signs of malignancy. Conclusion: When a tumour of the anal margin of unknown origin is found, it is opportune to consider, although very rare, the adenomas that mimic the mammary tissues