CT of gastric masses: image patterns and a note on potential pitfalls.

Computed tomography (CT) was performed in 9 consecutive cases of primary gastric neoplasm. Lesions were surgically or endoscopically proved; cross-sectional images are correlated to specific histopathology in each case. The CT images of leiomyoma and leiomyoblastoma are characterized as models of pure bulging intramural growth resulting in a lunate contrast distribution when imaged in the cross-sectional plane. In 5 cases of lymphoma, distortion of the contrast-filled hollow viscus is relatively consistent. Nodular growth is reflected on the CT image as a series of digitations encroaching on the opacified portion of the gastric lumen. Image pattern recognition, relative to histopathology, is of more than academic interest since endoscopy is frequently unreliable in cases of submucosal and exophytic pathology. Further, biopsy of such lesions is commonly nondiagnostic as a result of random choice of biopsy site or inadequate depth of tissue sample. Additionally, this report includes images of lesions that simulate the primary gastric pathology and may be a source of erroneous interpretation. These include: pseudocyst of the pancreas (2 cases) and enlargement of the left lobe of the liver with encroachment on the gastric lumen (1 case). Image specificity on CT examination is increasingly essential to diagnosis and surgical planning.