ABSTRACTEsophageal neuroendocrine carcinoma is very rare and highly aggressive. An 85-year-old man with a history of esophageal squamous cell carcinoma in remission presented 4 years after definitive chemoradiation with new-onset dysphagia. Endoscopy with biopsy revealed high-grade malignancy consistent with neuroendocrine carcinoma. Treatment options were limited to chemotherapy because of his metastatic disease, and he unfortunately died 14 months after diagnosis. The occurrence of esophageal neuroendocrine carcinoma in a site of prior squamous cell carcinoma is very uncommon, and this likely represents a case of radiation-induced malignancy. Therefore, when undergoing radiotherapy, patients and providers should discuss the possibility of this life-threatening complication.