Neuroendocrine Carcinomas of the Esophagus: Clinicopathological and Immunohistochemical Features of 43 Cases

Background Neuroendocrine carcinomas (NECs) of the esophagus are extremely rare and poorly understood. This study aimed to delineate the clinicopathological and immunohistochemical features of esophageal NECs using a retrospective survey. Methods Patients with histologically proven esophageal neuroendocrine carcinomas (NECs) were recruited from Zhongshan Hospital, Fudan University, China, between 2006 and 2016. Clinical, endoscopic, pathological, and immunohistochemical data were collected retrospectively. Results Of 43 patients with NEC, older male patients were predominant. In total, 93.0% of the tumor masses were located in the middle or lower esophagus. Twenty-nine (67.4%) and 22 (51.2%) cases showed ulceration and esophageal stenosis, respectively. The average index of Ki-67 staining was 67.1% ± 21.4% with positive immunostaining for CD56 (88.4%), chromogranin A (51.2%), and synaptophysin (72.1%). Small cell carcinomas accounted for 95.3% of cases, and 16.3% of patients had mixed components with adenocarcinoma or squamous cell carcinoma. Conclusion Esophageal NECs are rare and mainly affect men in their sixties or seventies. They show a similar endoscopic appearance to squamous cell carcinoma or adenocarcinoma and present with a proliferative mass with stenosis or ulcers. Therefore, esophageal NECs are difficult to diagnose by endoscopy. Esophageal NECs can be mixed with other subtypes of neoplasms, such as adenocarcinoma and squamous cell carcinoma. In addition to chromogranin A, synaptophysin, and CD56, NSE, S100, and CKpan might be candidate biomarkers to diagnose esophageal NECs. Overall, we provide new insights into the biology of esophageal NECs.