Endocrine tumors of the gastrointestinal tract

Endocrine tumors of the gastrointestinal tract are among the most interesting and heterogeneous of human malignancies. Presenting in highly variable fashions, carcinoid tumors and pancreatic endocrine tumors share natural histories that may range from the serendipitously found, easily cured appendiceal carcinoid to the highly malignant pancreatic islet cell tumors associated with unique endocrine syndromes. The heterogeneity and the relative rarity of these tumors hinder both basic and clinical research. However, new concepts of tumor biology, diagnosis, and treatment are emerging, which will lead to better understanding of the behavior of these tumors and, ultimately, to better treatment of the individual patient.