Role of abdominal computed tomography in evaluating left upper quadrant masses.

The etiology of abdominal masses in the left upper quadrant may be confusing because of the anatomic relationships of the organs involved. In three representative cases presented, computed tomography (CT) clearly defined masses as being nonurologic in origin, although conventional radiologic diagnostic techniques originally yielded results that suggested a renal or adrenal origin. In two other cases, masses thought to originate from the spleen or retroperitoneum were shown by CT to be renal tumors. In a sixth case, a large mass thought to be of renal origin but not evaluated by CT was found at surgery to be a pancreatic cyst. Abdominal CT is more sensitive than other imaging modalities in clarifying organ relationships and the origin of masses in the left upper quadrant.