Pneumomediastinum as first manifestation of emphysematous pyelonephritis in a patient who is non-diabetic

Abstract

Emphysematous pyelonephritis (EPN) is a rare but life-threatening acute suppurative infection of the kidney, characterised by production of gas within the renal parenchyma, collecting system or perirenal tissue. It has a high mortality rate (70% to 90%), and the majority of patients have diabetes mellitus. The left kidney is most common involved and Escherichia coli is the most common pathogen. EPN complicated with pneumomediastinum (PM) has been reported in only four cases previously. Here, a case of PM as first manifestation of EPN in a non-diabetic 81-year-old man is reported. He had experienced back pain and abdominal fullness for 1 week. A plain radiograph, CT aortography and MRI confirmed the diagnosis of EPN complicated with PM. The patient died on the 22nd day of treatment with antibiotics of cefmetazole, gentamycin and metronidazole.

Figure 1

Plain radiographs of thoracic and lumbar spines demonstrating pneumomediastinum (arrow in (A)) and air along the abdominal aorta over prevertebral regions (arrow in (B)).

Figure 2

CT scan of the aorta with intravenous contrast showing multifoci of air bubbles surrounding the distal aortic arch (arrow in (A)), thoracic aorta and mediastinum (arrow in (B)) and abdominal aorta (arrow in (C)), extending from the left renal hilum (arrow in (C)) and air bubbles within the parenchyma of non-enhanced left kidney (arrow in (D)).

Figure 3

MRI of thoracic and lumbar spines showing multifoci of air bubbles along the thoracic and abdominal aorta in T1-weighted and T2-weighted images (arrows in (A) and (B)) and periaortic regions (arrow in (C)).