Neuroendocrine tumors of gastrointestinal tract: the paradigm that lasts

Historically, the tumors that were morphologically different and clinically less agressive than the more common gastrointestinal adenocarcinomas were clasified under carcinoid tumors. However, the development of molecular biology tehniques revealed the heterogeneity of these tumors on cellular and subcellular level and ther different biological behaviour. Neuroendocrine tumors of gastrointestinal tract originated from neuroendocrine cells scaterred across the gastrointestinal mucosa. As a result these tumors were capable of secreting many different neurotransmiters, which may or may not be biologically active. The incidence of gastrointestinal NETs has been incresing over the last 2 to 3 decades. Patients often presented with vague, nonspecific symptoms which resulted in delayed diagnosis and adequate treatment. In this article, we discuss the nature of gastrointestinal NETs, clinical presentation, treatment options and prognosis.