Neuroendocrine neoplasms of the larynx: An overview

Abstract

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.

Large Cell Neuroendocrine Carcinoma of the Larynx: Definition of an Entity

“…The WHO classification of LNEC [1] generally follows that for pulmonary neuroendocrine carcinoma [2]: typical carcinoid (TC), atypical carcinoid (AC), and small cell carcinoma, corresponding to well-, moderately-, and poorly-differentiated neuroendocrine carcinoma, respectively. According to WHO classification of head and neck tumors and several other proposed classification systems [1,3], laryngeal tumors termed AC or moderately differentiated neuroendocrine carcinoma (MDNEC) would include neoplasms that, if lung diagnostic criteria were applied, would fulfill the diagnostic criteria of large cell neuroendocrine carcinoma (LCNEC). To our knowledge, differences in biologic behavior and patient outcome between these two distinct morphologic entities, MDNEC and LCNEC, have not been investigated in the larynx.…”

Laryngeal Paraganglioma: A Rare Clinical Entity Managed by Supraselective Embolization and Lateral Pharygotomy

“…Cytokeratin, epithelial membrane antigen, carcino-embryonic antigen are negative in paragangliomas while positive in carcinoids and small-cell neuroendocrine carcinoma [25]. Chromogranin, synaptophysin, neuron-specific enolase are positive in all the laryngeal neuroendocrine tumors [25].…”

“…S-100 testing is particularly necessary to establish the correct diagnosis as its negative in typical and atypical carcinoid and small-cell neuroendocrine carcinoma [25]. Cytokeratin, epithelial membrane antigen, carcino-embryonic antigen are negative in paragangliomas while positive in carcinoids and small-cell neuroendocrine carcinoma [25].…”

Primary neuroendocrine small cell carcinoma in larynx: case report and literature review

“…In addition, small cell neuroendocrine carcinoma may be positive for thyroid transcription factor-1 3,4 . Our case showed a specific immunohistochemical pattern with a positive cytoplasmic granular staining for synaptophysin and chromogranin A, positivity for a cytokeratin, AE1/AE3, and a high proliferation index (Ki67) that confirmed the histopathological diagnosis.…”

“…Laryngeal tumors with neuroendocrine morphology are a rare and diverse group of neoplasms, which share specific pathological and immunohistochemical features, with prognosis dependent on the tumor type. They have received increasing attention in recent years because of a controversial terminology that was in need of standardization 4 . Small cell carcinoma neuroendocrine type (SCC-NET) is a rare tumor (2.5-4% of all small cell carcinomas) and, according to one study, during the past 30 years only 160 cases of primary small cell carcinoma of the larynx have been published worldwide 2 .…”