Primary malignant melanoma of the larynx

Primary malignant melanoma of the larynx is a rare clinical entity. Only 53 cases have been reported in the medical literature to date. This report de scribes a case of primary malignant melanoma arising in the larynx and diag nosed by histologic examination of an excisional biopsy specimen. The patie nt was a 53-year-old man with a history of smoking and hoarseness. There wa s no clinical evidence of other primary malignant melanocytic lesions. Micr oscopically, the tumor consisted of polygonal-epithelioid cells admired wit h more elongated, spindle-shaped cells. The majority of the cells demonstra ted dark brown cytoplasmic and nuclear melanin. Marked pleomorphism and abn ormal mitoses were also identified. Despite significant ulceration and disr uption of the epithelium, in situ malignant melanocytes were recognized wit hin the remaining portion of the epithelium. Immunohistochemical studies we re positive for S100, HMB-45, and vimentin, while cytokeratin and iron stai ns were negative. Based on the clinical and histologic findings, a diagnosi s of primary malignant melanoma of the larynx was established.