Small cell neuroendocrine carcinoma of nose and paranasal sinuses: a study of three cases with short review of the literature

Small cell neuroendocrine carcinoma of the paranasal sinus with intraoral involvement: Report of a rare case and review of the literature

The diffuse neuroendocrine system continues to be an enigmatic topic of study in pathology due to its controversial embryologic origins, biology and a variety of tumors engendered. Originally thought to be localized to the classic neuroendocrine organs (pituitary, thyroid, pancreas and adrenal medulla), the neuroendocrine cells are now known to be distributed in every organ system of the body. A number of human diseases have been linked to aberrations in the functioning of the neuroendocrine cells. Neoplasms of the neuroendocrine system can thus occur in myriad primary sites and range in behavior from benign to lethal. Small cell neuroendocrine carcinoma (SNEC) is a high-grade neuroendocrine tumor, rarely presenting in the sinonasal region. This article reports a case of a 68-year-old male patient with primary paranasal SNEC showing intraoral involvement. The diagnosis is based on a thorough clinical, histopathological and immunohistochemical workup to differentiate it from the other small round blue cell tumors.

Meta-analysis of 701 published cases of sinonasal neuroendocrine carcinoma: The importance of differentiation grade in determining treatment strategy

The aim of this meta-analysis was to provide treatment guidelines for sinonasal neuroendocrine carcinoma (SNC) by combining all available data in the literature. A literature search for all studies concerning SNC was performed against the MEDLINE and EMBASE databases. Available clinical data was normalized, pooled, and statistically analyzed. A total of 701 cases of SNC were available for analysis, comprising 127 well or moderately differentiated sinonasal neuroendocrine carcinomas (SNEC), 459 sinonasal undifferentiated carcinoma (SNUC) and 115 sinonasal small cell carcinoma (SmCC). Tumor type was the most important predictor of survival, with a 5-year disease-specific survival (DSS) of 70.2% for SNEC, 35.9% for SNUC and 46.1% for SmCC. Tumor stage on presentation was of limited value in predicting survival or response to treatment. Overall, the application of surgery yielded significantly better results (5-year DSS 52.2% versus 30.1%, p<0.001). In SNUC, radiotherapy was a beneficial supplement to surgery (5-year DSS 54.7% versus 15.7%, p=0.027), while radiotherapy as monotherapy performed poorly (5-year DSS 17.9%). Chemotherapy did not appear to contribute to survival. Based on these findings, we can conclude that the most important predictors of survival in SNC are differentiation grade and the associated choice of treatment modality. In contrast to other head and neck cancers, tumor staging appears of limited value in predicting survival or deciding on a treatment strategy. Surgery should be the cornerstone of treatment, supplemented by radiotherapy in poorly differentiated subtypes (SNUC, SmCC). Chemotherapy does not appear to contribute to survival.