Imaging findings in a malignant carcinoid depend on its size, the degree of mesenteric invasion/desmoplastic reaction, and the presence of regional lymph node invasion. Gastric carcinoid Imaging findings are nonspecific and depend on the type of tumor. On barium meal examination, the most common finding is a single, intramural, sharply demarcated defect that is usually 2-3 cm in diameter. In type I disease, multiple sessile polypoid lesions of varying sizes may be seen arising from the wall of the stomach. Esophageal carcinoid Tumors may present as intraluminal, extramucosal filling defects on barium studies. Small-bowel carcinoid Plain abdominal radiographs may reveal curvilinear calcification within the abdomen. On barium studies, findings consist of fairly well-defined, round, intraluminal bowel-filling defects. These may be associated with thickening of the valvulae conniventes resulting from interference of the bowel blood supply by the tumor.