Asymptomatic renal abscess: evaluation with gadolinium DTPA-enhanced MRI.

Incidental detection of renal mass in a transplant patient is a diagnostic challenge. These patients are at risk for the development of neoplasms and, more commonly, infection with atypical organisms. Symptomatology may be lacking in either, and both conditions may present with similar symptoms. Magnetic resonance imaging (MRI) evaluation with gadolinium DTPA is helpful in the evaluation of asymptomatic renal mass, with enhancement effectively excluding simple and hemorrhagic cysts. Because the MRI appearances of renal cell neoplasm and renal abscess overlap, both must be considered in the differential diagnosis.