PADUA, ITALY

Neuroendocrine neoplasms of the larynx have been divided into those of epithelial or neural origin. The latter consist of the paragangliomas. The group of epithelial origin can be divided into typical and atypical carcinoids and small cell neuroendocrine carcinoma, the latter consisting of the oat cell type, the intermediate cell type, and the combined cell type. Approximately 500 cases of these tumors have been reported in the literature. The diagnosis is based substantially on light microscopy. In some instances, it may be supported by special histochemical reactions. It must be confirmed by immunocytochemical and ultrastructural investigations. The different biological behavior of neuroendocrine neoplasms of the larynx makes a specific diagnosis of paramount importance, since treatment depends on diagnostic accuracy. Typical carcinoid is an extremely rare lesion. It is treated preferably by conservative surgery, and elective neck dissection is not necessary because of the lack of lymph node metastases at diagnosis. Chemotherapy and! or radiotherapy have not been effective in the limited number of patients so treated. Atypical carcinoid is the most frequent non-squamous carcinoma of the larynx. The mainstay of treatment is surgery. Elective neck dissection should be performed because of the high likelihood of cervical lymph node metastases. Primary radiation therapy with adjuvant chemotherapy is not indicated. The survival rate is 48% at 5 years and 30% at 10 years. Although the larynx is one of its most common extrapulmonary sites, small cell neuroendocrine carcinoma is still a rare tumor. Surgical results for this tumor have been disappointing, and surgery is reserved for cases of local relapse with no evidence of metastasis. Chemotherapy and radiotherapy currently appear to offer the least disabling and most effective forms of therapy. The 2-and 5-year survival rates are 16% and 5%, respectively. Paraneoplastic syndromes have occasionally been reported in association with carcinoid tumors (typical and atypical) and small cell neuroendocrine carcinoma, and there have been rare reports of elevated serum levels of neuropeptides. Paraganglioma is the only laryngeal neuroendocrine neoplasm with a female preference (3:1). Confusion with atypical carcinoid has led to incorrect diagnosis and inappropriate classification schemes, erroneously suggesting that laryngeal paraganglioma has the potential for aggressive behavior. Conservative surgery represents the treatment of choice, and elective neck dissection is not necessary. The prognosis is excellent.