CHGA and pancreatic neuroendocrine tumor: Currently, the histopathology of PHNET can refer to other NETs in the “Chinese Gastrointestinal Pancreatic Neuroendocrine Tumor Expert Consensus (2022 Edition)”; chromogranin A, Syn, and CD56 are currently recognized as specific immunohistochemical markers for diagnosing NET, and this case is consistent; The diagnostic grading of NETs has clear reference standards, which will not be elaborated here.