Primary moderately differentiated neuroendocrine carcinoma (atypical carcinoid) of the larynx: A case report with immunohistochemical and molecular study.

Neuroendocrine tumours are the second most common laryngeal neoplasms, following squamous carcinoma. In this paper, we report the case of a moderately differentiated neuroendocrine carcinoma NEC (atypical carcinoid) of the larynx in a heavy smoker 67-year-old woman, with a history of hoarseness, dysphagia and dyspnea. The lesion was biopsied and microscopic examination revealed moderately differentiated NEC; thus the patient underwent supraglottic laryngectomy with lymphadenectomy. Here, we emphasized the morphological criteria for a correct pathological diagnosis. Moreover, because it has been demonstrated that many neuroendocrine neoplasms and malignant lesions of the larynx can be related to human papilloma virus (HPV), for the first time, we probed to verify if laryngeal neuroendocrine carcinoma could be due to an HPV infection by using polymerase chain reaction amplification (PCR) of tumoural DNA. On immunohistochemical analysis, the lesion characteristically revealed both neuroendocrine and epithelial differentiation with diffuse staining for chromogranin A, synaptophysin and neuron-specific enolase (NSE) and epithelial membrane antigen (EMA) and overexpression of p53 protein. PCR of NEC DNA did not show any signal for HPV DNA. Thus, this neoplasm is not due to an HPV infection, but a mutation of p53 gene which could cause immunohistochemical overexpression of p53 protein.