Gastrointestinal conventional carcinoma with neuroendocrine differentiation: From pathological phenomenon to clinical importance (Review).
Conventional carcinomas that lack neuroendocrine morphological features but display detectable expression of neuroendocrine markers through immunohistochemistry are termed conventional carcinomas with neuroendocrine differentiation (NED). Distinguishing these from mixed neuroendocrine non-neuroendocrine neoplasms and amphicrine-like carcinomas is important in accurate diagnosis and clinical management. The present review systematically outlines the advancements in research on gastrointestinal conventional carcinomas with NED, focusing on their characteristics, diagnostic criteria and clinical features. The present review further summarizes the epidemiological and clinical aspects across numerous organs such as the stomach and colorectum, emphasizing common mechanisms and prognostic variability. The future prospects of gastrointestinal conventional carcinomas with NED are also discussed, concentrating on key mechanisms, molecular subtypes and ongoing clinical trials to influence future research and clinical practices.