Oncocytic and oncocytoid carcinoid tumors (well-differentiated neuroendocrine carcinomas) of the larynx.

Carcinoid tumors of the larynx are exceedingly rare neoplasms. With the inclusion of the five neoplasms we report herein, the total number reported in the English-language literature is 16. These five neoplasms all showed light microscopic features of oncocytic (or oncocytoid) cells. Ultrastructurally, all lesions contained dense-core granules of the neurosecretory type. One case further met the ultrastructural criteria for true oncocytoma (that is, an oncocytic carcinoid). The lesion did not metastasize, and the patient was successfully treated surgically. In the other four cases, the lesions were considered to be oncocytoid carcinoids, since they failed to meet the ultrastructural requirements of a true oncocytoma. Each of these four lesions metastasized, although one patient did have a long, indolent course.