Hidradenoma papilliferum: an unusual benign perianal tumour.

Hidradenoma papilliferum is an uncommon benign tumour that is located in the anogenital region of middle-aged women. They are usually only diagnosed after excision and are thought to arise from anogenital mammary-like glands. We present the case of a young woman who noticed a slow growing perianal lump which caused minimal symptoms.