Laryngeal primary malignant melanoma: a case report.

Malignant melanoma of the larynx is a rare cancer that can appear as a primary tumor or as a metastasis from a cutaneous head and neck primary lesion. We present a new case of primary laryngeal malignant melanoma diagnosed by histological examination of an excisional biopsy specimen. The patient was a 53-year-old man with a history of smoking and hoarseness but without any clinical evidence of other cutaneous malignant melanocytic lesions. Microscopically, the tumor consisted of polygonal-epithelioid cells admixed with more elongated, spindle-shaped cells. Some of the tumoral cells demonstrated dark brown cytoplasmic and nuclear melanin. Despite significant ulceration and disruption of the epithelium, in situ malignant melanocytes were recognized within the remaining epithelium. Immunohistochemical stains were strongly positive for S-100 protein, HMB-45 and Melan-A. On the other hand, cytokeratin stains were negative. Based on the clinical and histological findings, a diagnosis of primary malignant melanoma of the larynx was established.