Ileo-vesical fistula secondary to squamocellular bladder carcinoma

Clinical History

Middle-aged woman with chronic kidney disease (glomerular filtration rate ~20 ml/min) from untreated hypertension, currently suffering from dysuria, orange-coloured urine and suprapubic pain. Physically found hypotensive and dehydrated.
Laboratory evidence of anaemia (9 g/dl haemoglobin), leukocytosis (22000 cells/mmc), raised C-reactive protein (32 mg/l) and markedly abnormal urinalysis.

Imaging Findings

As sonographically suspected by the attending gynaecologist, initial noncontrast CT (Fig. 1) showed marked (1 cm) mural thickening along the right posterolateral and superior aspects of the urinary bladder, closely adherent to non-dilated small bowel loops, and intraluminal air without recent catheterisation.
Cystoscopy revealed markedly irregular right wall, abundant fibrous material and fecaloid urine in the lumen, right wall irregular, fecaloid urines without identifying frank fistulous orifices. After hydration, contrast-enhanced CT (Fig. 2) confirmed marked mural thickening of the urinary bladder consistent with biopsy finding of muscle-invasive poorly differentiated cancer, and contrast injection via Foley catheter opacified a double, wide fistula connecting the bladder dome to the ileum.
Radical cystectomy en-bloc with ileum and uterus, lymphadenectomy and Bricker diversion was performed (Fig. 3). Histology diagnosed a 10x6 cm bladder squamocellular carcinoma with full-thickness mural involvement and infiltration of peritoneal serosa, perivisceral fat and ileum (pT4N2).

Discussion

Entero-vesical fistulisation refers to the formation of an abnormal communication between the urinary bladder and either the small or large bowel. Its characteristic symptoms include persistent urinary infection, pneumaturia, fecaluria and abnormal urinalysis including haematuria. Sigmoid colon diverticulitis and Crohn’s disease (CD) by far represent the most common causes of colo-vesical and ileo-vesical fistulas (IVF), respectively. In elderly patients and adults without CD, an IVF is very uncommon: as described in sparse case reports, causes include ileal (including Meckel’s) diverticula, small bowel cancer and lymphoma, previous pelvic irradiation and post-chemotherapy changes. [1, 2]
The hereby reported IVF caused by a bladder cancer is particularly exceptional, due to the rare (below 5% incidence in Europe) squamocellular histology, which is generally related to chronic urinary or Schistosoma infection, and associated with advanced muscle-invasive disease at presentation and unfavourable prognosis. [3, 4]
Currently, most patients are studied using CT and entero-vesical fistulisation is generally suggested by the presence of air in the urinary bladder without catheterisation or recent instrumentation. Other signs include passage of oral or rectally administered contrast medium, mural thickening of the bladder and of adjacent bowel tract, presence of an air-containing extraluminal mass. Fistulas connecting to the right and anterior aspects of the bladder are mostly originated by ileo-caecal diseases; conversely, rectosigmoid processes tend to track to the posterior, superior and left-sided aspects of the bladder. Furthermore, as in this case vesical fistulisation is easily confirmed by conventional radiographic or better CT cystography using iodinated contrast administered through Foley catheter. From the oncologic perspective, invasion of adjacent organs (such as the bowel, female genitalia, prostate and seminal vesicles) represents T4 stage tumour. [4-6]
Outside the setting of CD, ileo-vesical fistulas generally require surgical intervention to relieve debilitating symptoms and prevent further morbidity. Malignancies generally require en-bloc resection. Palliative radiotherapy, diverting enterostomy and permanent bladder catheterisation are reserved for elderly and inoperable patients. The prognosis is poor, particularly in node-positive tumours. Interestingly, albeit the female gender is less likely to develop urinary bladder cancer than males, women tend to present with more advanced disease and have worse survival rates. [3, 4, 7]

Differential Diagnosis List

Final Diagnosis

Squamocellular bladder carcinoma with ileo-vesical fistulisation.

URL:	https://eurorad.org/case/15665
DOI:	10.1594/EURORAD/CASE.15665
ISSN:	1563-4086