Neuroendocrine tumors of the luminal gastrointestinal tract.

Abstract

Neuroendocrine tumors (NETs) of the gastrointestinal tract have been recognized for more than a century. Despite histologic similarities between different sites in the tract, behavior varies between areas. All of these tumors have malignant potential, but determination of exact risk is difficult. To review the diagnosis of luminal gastrointestinal NETs, including a discussion of grading. Grading by mitotic index/activity, in conjunction with tumor size/stage, has been found to be the strongest predictor of behavior. Literature review of luminal gastrointestinal NETs was performed and the results summarized. Our understanding of these lesions is incomplete and continues to evolve.