Neuroendocrine carcinomas of the larynx. A study of two types, one of which mimics thyroid medullary carcinoma.

We studied 13 neuroendocrine carcinomas of the larynx. They constituted 59% of the 22 nonepidermoid carcinomas of the larynx seen at Memorial Hospital during a 45-year period, and for which adequate material was available for review. Four tumors were histologically identical to small cell carcinomas of the lung and were classified as small cell neuroendocrine carcinomas (SCNC). One case represents one of the original descriptions of the laryngeal SCNC. No SCNC was argyrophil, and of the three studied immunohistochemically, all contained neuron-specific enolase, one carcinoembryonic antigen (CEA) and one serotonin. Nine tumors were large cell carcinomas (LCNC). Eight LCNC were argyrophil, and all nine contained neuron-specific enolase, six calcitonin, four CEA, one HCG, two serotonin, and two somatostatin. The laryngeal neuroendocrine carcinomas commonly presented in chronic cigarette smokers with mean ages of 63 (SCNC) and 60 (LCNC), were not associated with other endocrine tumors, and proved highly fatal in spite of radical surgery and radiation therapy. At last follow-up only one patient was alive (after 13 months). Patients dying with SCNC survived a mean of 11 months, and those with LCNC, 36 months. To determine whether the laryngeal LCNC most closely resembles pulmonary neuroendocrine tumors, head and neck paragangliomas, or thyroid medullary carcinoma (TMC), they were histologically, histochemically, and immunohistochemically compared with control cases of each group. Overall, LCNC most closely resembles TMC, and given the frequency with which each presents as a neck mass, misinterpretation of one for the other is very possible. Evidence is provided suggesting that some LCNC have also been mistaken for the laryngeal paraganglioma.