A Case of Melanoacanthoma on the External Auditory Canal / 대한피부과학회지

ABSTRACT

Melanoacanthoma, a rare benign variant of seborrheic keratosis, was first introduced by Mishima and Pinkus in 1960. It is a slow-growing, painless, pigmented plaque with a verrucous surface and a diameter ranging from a few millimeters to 10 cm. It tends to develop during middle-age with an equal sex incidence, and the lesion usually presents on the head, trunk, and especially the lip. It also has a histopathologic finding of mixed neoplasm composed of melanocytes scattered throughout keratinocytic lobules, and is characterized by hyperkeratosis, parakeratosis, acanthosis, papillomatosis and pseudo-horn cysts in the epidermis. We report a case of melanoacanthoma occurring in a 52-year-old female, who presented with an easily bleeding mass on her right external auditory canal, an extremely uncommon site.