Carcinoid syndrome: advances in diagnosis and treatment.

Carcinoid is the most common endocrine digestive tumor. The carcinoid syndrome resulting from the variety of amines and peptides pr oduced by this tumor is usually apparent once there are metastases to the l iver. Tumors with direct systemic venous drainage seldom produce a carcinoi d syndrome without the presence of liver metastasis. This may occur because the hormone escapes the normal metabolic pathway (monoamine oxidase) in th e liver. The most significant and important advance in diagnosis for tumor localizat ion has been the introduction of scinthigraphy using In-111-labeled octreot ide. Current management of carcinoid syndrome should consider the spontaneous co urse of the disease and the severity of clinical symptoms, and includes dif ferent therapeutic options as hepatic resection, chemoembolization, medical treatment with the long-acting analogues of somatostatin and liver transpl antation.