[Pneumoperitoneum: infrequent complication of lithiasic pyonephrosis].

A case of lithiasic pyonephrosis evolving with intrapyelic gas formation, with positive urinary culture for Escherichia coli, is presented. Original clinical presentation was a picture of acute peritonitis with pneumoperitoneum. Clinical and radiological findings were indicative of exploratory laparotomy. The picture was resolved surgically, the procedure adopted being nephrectomy with retroperitoneal space drainage and empirically chosen antibiotics. The paper establishes the uncommon nature of this complication, and includes a literature review.