Imperforate hymen complicated with pyocolpos and lobar nephronia.

An imperforate hymen is not a rare condition in female newborns, but is often ignored in a genital examination by physicians. Lobar nephronia is a rare condition in pediatric patients that can be screened by ultrasound or computed tomography to distinguish it from a renal abscess. Treatment for lobar nephronia requires at least 14 days of antimicrobial therapy and a follow-up assessment by renal ultrasonography or dimercaptosuccinic acid scan. We report an unusual case of a 2-year-old girl with an imperforate hymen and pyocolpos. The pyocolpos compressed the left lower ureter to cause hydroureter, hydronephrosis, and nephronia. Partial hymenotomy was performed to drain the pus, and antibiotics were administered for a total of 3 weeks. There was a good outcome. This case demonstrates the need to perform a full physical examination, particularly a genital examination, in newborns. Further, if gynecologic pathology is suspected, then urologic screening studies are recommended to rule out potential associated anomalies.