[Carcinoid syndrome in neuroendocrine tumors--not easy to recognize].

Neuroendocrine tumors (NET) are solid potentially malignant tumors originated from the diffuse neuroendocrine system. They could origin in many organs, with highest prevalence in lungs, small intestine and rectum. Characteristics of NET are slow growth, non-specific clinical presentation causing diagnostic problems. Thus, in majority of patients diagnosis is established in the metastatic phase of the disease. Hopefully, there are new and very potent treatment options capable to successfully control the disease. Clinical presentation cause local tumor growth or para-neoplastic syndrome. Secretory active tumors produce peptides or hormones causing different clinical syndromes. In most cases NET cause carcinoid syndrome. It is often misinterpreted, because similar symptoms are present in more prevalent disorders. Symptoms are not specific and include flashing, diarrhea, abdominal pain, right heart disease, bronchoconstriction ... and to establish the right diagnosis medical doctor have to think about NET as a possibility. Thus, it is very important to recognize symptoms and signs of the carcinoid syndrome, and distinguish them from other gastrointestinal disorders. Early diagnosis and treatment have significant impact in control of the disease, and overall treatment results.