Vulva, Papillary hiradenoma

Papillary hiradenoma is the most common benign lesion in the vulvar region. They are also described as mammary-like gland adenoma, and they are thought to have derived from mammary-like anogenital glands.

The morphology is notable for the complex growth of tubules, formed by cuboidal to columnar cells. Areas of apocrine differentiation are also noted. Like the breast, outer cuboidal myoepithelial layers are present in these lesions, and they can be highlighted by the same myoepithelial markers, for example, p63.

Malignant transformation has been described, although it is very rare. Local excision is generally sufficient for management.