Hidradenoma papilliferum (HP) is a rare, benign cystic tumour that occurs predominantly in women aged 30 to 60. 1 It is thought to originate from anogenital mammary-like glands, and therefore most commonly arises in the anogenital region with vulvar lesions reportedly four times more frequently than perianal lesions. 2 It usually presents as a slow-growing solitary, circumscribed nodule with size ranging between 0.5 cm and 2 cm. 3
Wong et al. (Sun,) studied this question.