Emphysematous cystitis in an 64-year-old female patient

Clinical History

A 64-year-old female patient presented in our emergency department with fever, abdominal pain and dysuria for the past 5 days. Her past medical history included hypertension, unbalanced diabetes mellitus and breast cancer treated 10 years before. Her temperature was 38°C, the abdomen was soft but painful on palpation and there was no evidence of peritonitis.

Imaging Findings

Axial CT of the pelvis without contrast (Fig. 1) and after contrast administration (Fig. 2) showed intraluminal and intramural gas in the bladder with thickening of bladder wall and formation of an air-fluid level, which suggested a diagnosis of emphysematous cystitis. Axial pelvis CT in the late injection time (Fig. 3) showed gas collection within the wall and lumen of the bladder. There were no other abnormalities such as colovesical or vaginovesical fistula. Abdominal axial CT of the kidneys in the parenchymal injection time (Fig. 4) eliminated associated renal abnormality.

Discussion

Emphysematous cystitis is an uncommon infectious disease of the urinary bladder characterized by gas collection within the bladder wall and lumen produced by bacterial or fungal fermentation [1]. It affects women more frequently than men with a sex ratio of 2/1 [2].
Diabetes mellitus is the most common predisposing factor identified in the literature [3].
Other risk factors include neurogenic bladder, urinary stasis, lower urinary tract obstruction, urethral catheter placement, vesicourethral reflux and renal insufficiency [4].
The mechanism by which gas appears in the wall of the bladder includes elevated tissue glucose levels in diabetic patients which may provide a more favourable microenvironment for gas-forming microbes [3]. Also, urinary albumin may be a substrate in non-diabetics. Another suggested factor promoting gas production is an impaired host response, involving vascular compromise and impaired catabolism within the tissues [4].
The imaging methods play an important role in diagnosis of emphysematous cystitis.
Plain abdominal and pelvic radiography can show air fluid levels in the bladder or a typical cobblestone appearance. A rim of gas lucency outlining the wall of the bladder can suggest the diagnosis although the presence of bowel gas can be a problematic feature [5].
Ultrasonography usually shows bladder wall thickening with marked echogenicity, but the sensitivity of this sign is low (46%). A pathognomonic sign of circumferential, acoustic shadowing around the bladder wall is rarely noted [6, 7].
Computed tomography of the abdomen is superior to plain X-ray as a diagnostic tool because it defines the extent and location of the gas collection more precisely. CT can clearly depict air in the bladder lumen or wall, and also the complication of gas presence. The sensitivity of CT is high, even with non-contrast-enhanced CT.
Also, CT can differentiate emphysematous cystitis from emphysematous pyelonephritis, in which gas involves the renal parenchyma [5].The emphysematous pyelonephritis has an increased mortality [8].
Emphysematous cystitis should be differentiated from pneumaturia which is mostly due to communication of the bladder with a hollow organ by bladder-intestinal or vaginal fistula [9].
Treatment should be as early as possible for a favourable evolution. It consists of urinary drainage, antibiotic treatment, and good blood glucose control. The prognosis of emphysematous cystitis is usually good with an improvement of the patient’s condition within the first week. Complications of delayed diagnosis may be extension of infection to the ureters and renal parenchyma, bladder rupture, and death [10].
In conclusion, CT remains the best method for diagnosis, also for defining the severity and guiding the appropriate treatment.

Differential Diagnosis List

Final Diagnosis

Emphysematous cystitis

URL:	https://eurorad.org/case/12927
DOI:	10.1594/EURORAD/CASE.12927
ISSN:	1563-4086