Hidradenoma papilliferum occurring on the nasal skin.

Hidradenoma papilliferum is a rare benign neoplasm that usually occurs in the female anogenital area. We present a 43-year-old female with a non-anogenital (ectopic) hidradenoma papilliferum on her nose. The patient had had a skin-colored subcutaneous nodule on her nose for 7 years. The histopathological findings showed variously shaped cystic spaces in the tumor. And the lumina were surrounded by a single or double layer of cell which showed decapitation secretion. In the English dermatological literature, only one case of ectopic hidradenoma papilliferum arising in nasal skin has been reported. Hence we suggest hidradenoma papilliferum occurring on the nasal skin is a peculiar and interesting event.