CGA and neuroendocrine carcinoma: Of these 15 cases, a total of 9 were pancreatic, cervical, gastric, and CUP neuroendocrine carcinomas (NECs, an entity known to dedifferentiate and lose CGA immunoreactivity), 4 were WHO grade I colorectal neuroendocrine tumors (NETs; known to frequently lack CGA immunoreactivity), and two were neuroendocrine adenomas of the middle ear (NAMEs).