A 55-year-old man presents to the emergency department complaining of suprapubic abdominal pain. He notes that his symptoms began 3 days ago as right sided flank pain and dysuria and have since progressed. On examination, he is significantly tender to suprapubic palpation, has no costovertebral angle tenderness, and has an otherwise benign abdomen. A computed tomography (CT) scan of his abdomen to evaluate for renal stones was performed and the following images were obtained (figs 1 and 2).

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Figure 1

Scout film from non-contrast computed tomography (CT) showing a severely distended bladder.

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Figure 2

Axial image from the same CT showing gas both within the bladder and within the wall of the bladder.

Emphysematous cystitis is a rare manifestation of cystitis caused by gas producing bacteria, most commonly Escherichia coli.1 Patients typically present with vague symptoms of abdominal pain and dysuria.2 A history of pneumaturia is pathognomonic1 but rarely elicited and the diagnosis is usually made after radiographic evaluation.3 While it carries a 7% mortality rate, it is important to differentiate emphysematous cystitis from the even more severe emphysematous pyelonephritis, as the latter has a 20% mortality rate and is treated by nephrectomy.2 In contrast, emphysematous cystitis is typically managed conservatively with either percutaneous or urethral drainage of the bladder and parenteral antibiotic treatment.1

It is important to note that while infection is the most common cause, emphysematous cystitis can also be caused by trauma, vesico-enteric fistulas, carcinoma, and diagnostic or surgical instrumentation.4 As physical examination findings cannot exclude the disease, radiographic imaging should be obtained whenever emphysematous cystitis is on the differential diagnosis.4

A delay in the diagnosis can lead to ureteral or renal extension, bladder rupture, peritonitis, and death.