Secondary Nasopharyngeal Mixed Adenoneuroendocrine Carcinoma After Radical Radiotherapy for Nasopharyngeal Carcinoma: A Rare Case and Literature Review

Nasopharyngeal Large Cell Neuroendocrine Carcinoma Synchronized With Nasopharyngeal Squamous Cell Carcinoma: A Case Report and Review of Literature

Neuroendocrine carcinomas (NECs) are poorly differentiated neuroendocrine tumors of the upper respiratory tract. We present an extremely rare case of nasopharyngeal large cell neuroendocrine carcinoma (LCNEC) synchronized with nasopharyngeal squamous cell carcinoma (SCC). Both SCC and LCNEC are associated with Epstein-Barr virus (EBV) infection, supported by the positive result of Epstein-Barr encoding region in-situ hybridization. Strong correlation is found between EBV infection and nasopharyngeal malignancies. Furthermore, the EBV status might be a crucial prognostic factor in nasopharyngeal LCNEC. EBV-positive LCNEC is effective to chemoradiotherapy, and may have preferable outcome than EBV-negative LCNEC arising in the nasopharynx or other sites. The recognition of the EBV status is important for patients to receive appropriate treatment.

CT and MR imaging features of mixed neuroendocrine-non-neuroendocrine neoplasm of the pancreas compared with pancreatic ductal adenocarcinoma and neuroendocrine tumor

OBJECTIVE

This study aimed to assess the computed tomography (CT) and magnetic resonance imaging (MRI) features of pancreatic mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) and compare them with those of pancreatic ductal adenocarcinoma (PDAC) and neuroendocrine tumor (NET).

METHODS

Twelve patients with pancreatic MiNEN, 24 patients with PDAC, and 24 patients with NET, who underwent both contrast-enhanced CT and MRI, were included. Clinical data and the key imaging features were retrospectively evaluated by two independent readers and compared between MiNEN and PDAC or NET. Univariate and multivariable logistic regression analyses were performed to obtain predictors for pancreatic MiNEN.

RESULTS

Patients with pancreatic MiNEN more frequently presented with large size and heterogeneous and cystic components compared with PDAC (p < 0.031) and ill-defined irregular margins, progressive enhancement, and adjacent organ involvement compared with NET (p < 0.036). However, vascular invasion was less commonly seen in MiNEN than PDAC (p = 0.010). Moderate enhancement was observed more frequently in MiNEN than in PDAC or NET (p < 0.001). Multivariate logistic analyses demonstrated that moderate enhancement and ill-defined irregular margin were the most valuable features for the prediction of pancreatic MiNEN (p ≤ 0.044). The combination of the two features resulted in a specificity of 93.8%, sensitivity of 83.3%, and accuracy of 91.7%.

CONCLUSIONS

We have mainly described the radiological findings of pancreatic MiNEN with ill-defined irregular margin and moderate enhancement compared with PDAC and NET. The combination of imaging features could improve diagnostic efficiency and help in the selection of the correct treatment method.