[Symptoms and diagnosis of neuroendocrine tumors of the digestive system]

Neuroendocrine tumors of the digestive system can cause very diverse clinical symptoms. Due to the secretion of biogenic amines, peptides and hormones secreted by the tumor cells, various paraneoplastic syndromes can evolve, on the other hand, the growth and spreading of hormonally inactive tumors can result in different local symptoms. Patients can be symptom-free for a long time or aspecific, often periodical symptoms can prevent recognition or lead to misdiagnosis for years. The symptomatology of hormonally active tumors, derived mainly from the pancreas is very characteristic. Carcinoid syndrome can be seen in 10-18% of patients with neuroendocrine tumors. In this review, the critical appreciation of laboratory and imaging modalities is discussed. Among the major new developments in this field, the introduction of serum chromogranin A assay and new small bowel examination methods should be mentioned. Capsule endoscopy and balloon enteroscopy can provide possibility of much more earlier diagnosis, as previously. The worldwide spreading of endoscopic ultrasound and fine needle biopsy allows the detection and clear localization of pancreatic neuroendocrine tumors.