Enlarged accessory spleens: CT appearance in postsplenectomy patients.

An unexplained abdominal mass discovered on CT examinations of a postsplenectomy patient may represent a hypertrophied residual accessory spleen. Six such patients were found to have left upper quadrant masses on CT examinations that were subsequently proved to be enlarged accessory spleens. The CT appearance is that of discrete, solitary, rounded masses of uniform soft-tissue density in the left upper quadrant. Diameters of the masses were 3.5-5.0 cm. The splenic nature of such a mass can be confirmed by appropriate radionuclide imaging.