CARCINOID tumors have attracted much attention because of their endocrine activity and the unique symptoms that may result from their existence. Once considered benign, their malignant potential is now well appreciated.1 Radiologically, these relatively uncommon tumors can present a variety of appearances that are a reflection of both tumor growth and secondary tissue reaction. Preoperative diagnosis is notoriously difficult and requires a synthesis of clinical, laboratory, and radiological data.
The incidence of carcinoid tumors based on autopsy studies ranges from 0.08% to 1.36%. They are derived from cellular elements originating in the primitive neural-crest ectoderm. These cells migrate to several areas and belong to a family sharing the features of amine content, precursor uptake, and decarboxylation (APUD).2 Therefore, these carcinoid APUD neoplasms can occur in the gastrointestinal (GI) tract, GI derivatives (pancreatobiliary tract), and primordial GI derivatives (lungs, genitourinary tract, thymus). A consistently positive relationship between carcinoid neoplasms