Andrea Grin1, Catherine J Streutker. 1. From the Department of Laboratory Medicine and the Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
Abstract
CONTEXT: 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. OBJECTIVES: 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. DATA SOURCES: Literature review of luminal gastrointestinal NETs was performed and the results summarized. CONCLUSIONS: Our understanding of these lesions is incomplete and continues to evolve.
CONTEXT: 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. OBJECTIVES: 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. DATA SOURCES: Literature review of luminal gastrointestinal NETs was performed and the results summarized. CONCLUSIONS: Our understanding of these lesions is incomplete and continues to evolve.