[Acute focal bacterial nephritis (acute lobar nephronia) report of two cases].

Acute focal bacterial nephritis (AFBN) is one of the acute renal infections, its entity can be distinguished from other renal infections by the findings of sonography and computed tomography. There is no evidence of liquefaction in focal masses of AFBN in contrast to renal abscess. We present two cases with AFBN. The first case was a 52-year-old man with diabetes mellitus and benign prostatic hypertrophy. The second case was a 24-year-old woman with bilateral vesico-ureteral refluxes. Although their initial symptoms mimicked those of acute pyelonephritis, the findings of sonography and computed tomography revealed renal masses. They were treated with anti-microbial agents, and showed rapid improvement on both clinical symptoms and renal masses.