Abstract: This article focuses on neuroendocrine neoplasms and early cancer of the digestive system, and explores the relationship between rare and common diseases. By comparing the similarities and differences in clinical manifestations, endoscopic manifestations, biological behaviors and clinical outcomes between neuroendocrine neoplasms and early cancer of the digestive system, the potential association between rare and common diseases was revealed. This article aims to deepen the understanding of these two diseases, improve the detection rate of rare diseases such as neuroendocrine neoplasms, and promote their accurate diagnosis, thereby creating more opportunities for early intervention and treatment, and ultimately improving the prognosis of patients.