Presacral masses after abdominoperineal resection for colorectal carcinoma: the need for needle biopsy.

Computed tomographic(CT)-guided biopsy of presacral masses after abdominoperineal resection for colorectal carcinoma was performed in 28 patients, using a transgluteal approach. The masses were divided into three groups according to their morphologic appearance: solid mass, mass with central low-density area, and gas-containing mass. Of 19 patients with a homogeneous solid mass, 15 had biopsy-proven recurrent adenocarcinoma. In the other nine patients, who had low-density masses with or without gas, it was not possible to offer a diagnosis on the basis of the CT appearance alone. In these cases, needle biopsy disclosed various entities, including recurrent tumor, abscess, and posttreatment necrosis. There was only one complication, transient hematuria. CT-guided needle biopsy of presacral masses after abdominoperineal resection is a simple, relatively safe, and valuable diagnostic technique.