Esophageal Carcinoma with Small-Cell Neuroendocrine Carcinoma Component and Lymph Node Metastasis Mixed with Poorly Differentiated Squamous Cell Carcinoma: A Rare Case Report

This study reports a case of a 74-year-old male patient with esophageal carcinoma who presented two months before admission with dysphagia and chest pain during meals. Preoperative imaging and biopsy revealed a mixed esophageal neuroendocrine carcinoma and non-neuroendocrine carcinoma (squamous cell carcinoma, SCC), with small-cell neuroendocrine carcinoma (SCNEC) comprising the predominant component (65%). Based on the preferences of the patient and his family, surgical treatment was performed first. Postoperative pathological examination revealed poorly differentiated SCC as the predominant component (approximately 90%), with SCNEC accounting for about 10% and lymph node metastasis present, indicating that the NEC component exhibited marked aggressiveness. This case highlights the importance of multiple deep preoperative biopsies and calls for a reevaluation of the WHO definition of Mixed Neuroendocrine-Non-Neuroendocrine Neoplasm (MiNEN), particularly the 30% threshold. Further clinical studies are warranted to refine the diagnostic criteria and therapeutic strategies for MiNEN to improve patient outcomes.