Laryngeal paragangliomas and neuroendocrine carcinomas.

Forty-eight neuroendocrine tumours of the larynx were studied, of which 41 were classified as large cell neuroendocrine carcinoma. Most of these tumours occurred in the supraglottic larynx and the patients were predominantly male. Exquisite pain was a presenting feature in one third. These carcinomas metastasized, frequently to skin, giving rise to painful secondary lesions, but long-time survival occurred. Histologically, large cell neuroendocrine carcinoma had a number of features seen in neuroendocrine tumours at other sites, including grouping into 'Zellballen' which mimics paraganglioma. Four tumours were definite paragangliomas. These tumours have behaved benignly. There were three cases of small cell neuroendocrine carcinoma, a tumour which is histologically identical to its counterpart in the bronchus and has a very aggressive course. All three types of tumour expressed general neuroendocrine markers, but only large cell neuroendocrine carcinoma marked for both cytokeratin and calcitonin. In the paraganglioma cases sustentacular cells were identified and marked for S-100 protein and glial fibrillary acidic protein. Histological examination, supplemented with immunohistochemistry, helped distinguish these tumours into those requiring different treatment regimens.