Sonographic appearance of primary small bowel carcinoid tumor

To assess the value of sonography in the diagnostic work-up of small bowel carcinoid tumors and characterize their sonographic appearance.

We retrospectively reviewed the sonographic findings (size, shape, echogenicity, contour, location, wall thickening, serosal transgression, vascularity) of all cases of carcinoid tumors investigated between January 1988 and January 1993. Six tumors, in five patients with histologic proof, were analyzed and, when possible, correlation with pathological or surgical results was made.

In four out of five cases, the tumor was not suspected clinically prior to sonography; in one case, a small synchronous lesion was only found at surgery. Its sonographic appearance was a hypoechoic, homogenous, predominantly intraluminal mass with smooth intraluminal contour and attached to the wall by a broad base with interruption of the submucosa and thickening of the muscularis propria in all cases. There were signs of serosal transgression in four cases, puckering and retraction in two cases, hypervascularity in two cases, and mesenteric involvement in three cases. All lesions were located in the ileum and the mean diameter was 22 x 17 mm.

Ultrasonography was useful in the detection of primary carcinoid tumors of small bowel. Their sonographic characteristics were described and some of them were highly suggestive of the diagnosis.