Acute focal bacterial nephritis.

Clinical and radiographic characteristics of 12 patients with acute focal bacterial nephritis (AFBN) are presented along with review of the literature. Most patients presented with symptoms of an inflammatory or infectious process. Fever and pyuria were the most frequently encountered clinical characteristics. Imaging modalities that were used to establish a definitive diagnosis of focal bacterial nephritis included ultrasound, computed tomography, and intravenous urography with nephrotomography. Ultrasound was found to be the most effective and least costly method of diagnosis. Misdiagnosis of AFBN as abscess or tumor, which it may stimulate, could lead to inappropriate surgical therapy.