Pneumoretroperitoneum from a gas-containing retroperitoneal abscess

A 57-year-old man with diabetes mellitus presented with abdominal pain, fever, and chills for 3 days. Laboratory examinations revealed leukocytosis, hyperglycemia, and decreased renal function (blood urea nitrogen: 53.0 mg/dL, creatinine: 2.9 mg/dL). An elevated serum level of HbA1c (18.0%) was also noted. A plain abdominal radiograph disclosed a large area of mottled air on the right side of the abdomen and a crescentshaped area of air in the right upper quadrant of the abdomen [Figure 1]. Abdominal computed tomography showed a 5 mm-sized stone in the right ureterovesical junction and right hydronephrosis. Right renal parenchymal and pelvicalyceal defects were also noted. In addition, fluid and air accumulation indicating a gas-containing abscess were noted in the right side of the retroperitoneum [Figure 2]. Based on these findings, a right ureterovesical junction stone with obstruction and hydronephrosis, renal pelvicalyceal and parenchymal rupture, and retroperitoneal abscess were diagnosed. Abscess drainage was conducted, and Escherichia coli was found in the pus culture. The patient’s condition stabilized gradually with systemic antibiotics treatment and diabetic control during the course of hospitalization.