Differential diagnosis of huge abdominal masses visualized on CT scans.

Thirty-one consecutive cases of very large abdominal masses (greater than 10 cm in largest dimension) were identified from CT scans on 2145 patients performed over a 15-month period. All were malignant tumors. The most useful information derived from CT scans was the location and organ of origin. The tissue of origin could be predicted from knowledge of the organs expected in each abdominal quadrant or pelvic site. Our results indicate that CT is extremely useful in evaluating very large masses.