NEUROENDOCRINE NEOPLASMS OF THE LARYNX: AN OVERVIEW

Neuroendocrine neoplasms of the larynx are rare but are the most common nonsquamous tumors of this organ. In the past, there has been considerable confusion about the nature and classification of these neoplasms, but the current consensus is that there are 4 different types of laryngeal neuroendocrine tumors composed of paraganglioma, typical carcinoid, atypical carcinoid tumor, and small cell neuroendocrine carcinoma. Carcinoids and small cell neuroendocrine carcinomas are epithelial neoplasms, whereas paragangliomas are of neural origin. Diagnosis is based primarily on light microscopy and confirmed by immunohistochemistry and electron microscopy. Precise diagnosis is essential because the natural history, treatment, and prognosis vary widely for the different neoplastic categories. Typical carcinoids are very rare and are treated by wide local excision, usually partial laryngectomy, without elective neck dissection. Atypical carcinoid tumors are more common and more aggressive. They are treated by partial or total laryngectomy with elective or therapeutic neck dissection. Adjuvant chemo/radiotherapy may be of benefit in some cases. Small cell neuroendocrine carcinomas are highly aggressive and should be considered disseminated at initial diagnosis. The treatment is by irradiation and chemotherapy as surgery has proven to be of a little benefit. Paragangliomas are treated by local excision or partial laryngectomy. It is difficult to determine the valid survival statistics for typical carcinoids because of their rarity and confusion in the literature with their atypical counterparts. They have a greater tendency to metastasize, and thus a worse prognosis than was previously believed. Atypical carcinoid tumors have a 5-year survival rate of approximately 50%, which decreases with time. The prognosis of small cell neuroendocrine carcinoma of the larynx is dismal, with 5-year survival rates of 5%. The biological behavior of laryngeal paraganglioma is generally benign and the prognosis is excellent. (C) 2009 Wiley Periodicals, Inc. Head Neck 31: 1634-1646, 2009