Wide spectrum of neuroendocrine differentiation in identical appearing colon polyps: A report of 2 mixed endocrine-glandular polyps.

To the Editor, Mixed endocrine glandular tumors of the gastrointestinal tract are rare lesions. In these tumors, the glandular and neuroendocrine components display a broad spectrum of combinations with marked variability in histopathology, immunohistochemical properties and clinical prognosis. We hereby report two cases of colonic tubulovillous adenomas, concomitantly containing a neuroendocrine component. While one polyp contained benign microcarcinoid, the other showed a poorly differentiated infiltrative neuroendocrine cancer.