Polar infarct in a transplanted kidney: cause of a pseudomass.

Ultrasonography has become fairly standard for assessing common complications of renal transplantation such as hydronephrosis, urinomas, and lymphoceles. Infarctions are a less common complication that may occur in the setting of transplant rejection. We report a case in which an apparent solid mass on sonography proved to represent normal residual renal parenchyma in a kidney with a small shrunken lower pole due to infarction.