CARCINOID-TUMORS - IMAGING PROCEDURES AND INTERVENTIONAL RADIOLOGY

The hypervascular nature of carcinoid tumors and their metastases allo ws a more aggressive role by the radiologist in diagnosis and interven tional management. Double-contrast gastrointestinal studies still best define the primary neoplasms. Appendiceal tumors, the most frequent s ite of carcinoids, frequently escape radiologic detection until large enough to be discovered by computed tomography (CT). Superior mesenter ic arteriography of the small bower and cecum is useful when the scann ing procedures are not revealing. The ''spokewheel'' configuration of the desmoplastic mesenteric masses and lymph node metastases are best seen by CT, whereas hepatic metastases can be demonstrated by CT, CT-a ngioportography (CTAP), ultrasonography (US), magnetic resonance imagi ng (MRI), and octreotide scintigraphy. Percutaneous needle biopsy with radiologic guidance confirms the diagnosis of carcinoid tumors and th eir metastases. Hepatic arteriography; is frequently performed in prep aration for hepatic embolization or chemoembolization. Hepatic vascula r occlusion therapy, the procedure of choice for the management of ino perable carcinoid liver metastases, results in a partial response in a t least 50% of patients and a mortality rate of 5%. Chemoembolization with microencapsulated cytotoxic agents and direct percutaneous ethano l injection should also be considered for the treatment of liver metas tases.