Lentigo Malignant Melanoma Presenting with Cutaneous Horn

Verrucous Melanoma Presenting as a Cutaneous Horn

ABSTRACT

Verrucous malignant melanoma (MM) is a rare variant of melanoma that often presents diagnostic challenges. This case highlights the unique presentation of verrucous MM underlying a cutaneous horn. It is vital for dermatologists to be aware of this potentially benign-appearing variant to be able to diagnose and treat MM early on.

Cutaneous horn malignant melanoma

A 73-year-old Japanese woman presented with cutaneous horn on the right cheek. The resected tumor was 9 mm in diameter, with 14 mm protrusion, and showed exophytic growth with marked papillomatosis. Histopathology showed proliferation of atypical melanocytes with melanin pigments in the epidermis and dermis under the cutaneous horn. These cells were confined to the base of the cutaneous horn, and did not spread to the surrounding epidermis. The final diagnosis was cutaneous horn malignant melanoma. This pathological entity is considered a specific form of verrucous melanoma, and might be added to the list of cutaneous horn-forming lesions.