Aim: To review current terminology of mixed exocrine and endocrine tumors of the large intestine. Introduction: Previous classification of colorectal tumors contained category called “mixed adenoneuroendocrine carcinoma” (MANEC) which encompassed neoplasms of the large intestine with features of both adenocarcinoma and a neuroendocrine carcinoma. Indeed, the vast majority of the mixed colorectal tumors have these two malignant components. However, this designation is no more suitable as other combinations of neuroendocrine and non-neuroendocrine tumors are recognised. Material and Metods: A detailed review of the literature on classification of mixed neuroendocrine-nonneuroendocrine tumors has been done. Results: The nonneuroendocrine component in a mixed colorectal tumor can be either exocrine or squamous and can be either benign or malignant. The histological grade of the nonneuroendocrine component may also vary. Therefore in several recent papers a new term has been coined “mixed neuroendocrine-nonneuroendocrine neoplasms” (MiNENs) in order to convey all possible combinations of the two components. According to the histologically estimated malignant potential, MiNENs are further subdivided into three categories low grade, intermediate grade and high grade. Conclusion: The new terminology is much more comprehensible than the previous ones and ensures a more accurate assessment of biological behaviour of the mixed colorectal tumors thus avoiding overtreatment of clinically innocent lesions.

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