Bladder tumour in children

Clinical History

A 3-year-old girl presented with diffuse abdominal pain and dysuria.
There was no fever or abdominal pain on palpation, and no palpable abdominal mass.
Urinary cytology and haemogram were unremarkable.

Imaging Findings

Renal ultrasound (not shown on images) is unremarkable.
Vesical ultrasound demonstrates a hypoechogenic mass, heterogeneous, with ill-defined limits, occupying the left anterior wall of the bladder.
CT scan identifies a hypodense vesical lesion, with spiculated endoluminal limits, which enhances after contrast administration, especially in its anterior aspect and mucosa. There are small central areas of lower density that may correspond to areas of necrosis.
MRI shows a large bladder tumour that is iso / hypointense on T1 images and has heterogeneous hyperintensity on T2-weighted images.
The lesion has ill-defined limits, especially in the upper wall of the bladder, where there is densification of the adjacent fat and extra-bladder tumour growth.
On T2-weighted images, it is difficult to verify the integrity of the bladder wall, with small areas that lose their characteristic low signal.

Discussion

Inflammatory pseudotumour is a nonneoplastic proliferation of myofibroblastic and inflammatory cells with myxoid components. Adult patients are more frequent (mean age at diagnosis =40 years) and usually present with an ulcerating bleeding mass, haematuria, and voiding symptoms. Inflammatory pseudotumours also occur in children, and they can be almost asymptomatic in this population. Within the bladder, the lesion is locally aggressive and may mimic malignancy clinically, at cystoscopy, and at imaging. At imaging evaluation, inflammatory pseudotumour appears as a single bladder mass that tends to spare the trigone. It may be exophytic or polypoid and may be ulcerated. It is usually a hypoechogenic lesion on sonography, hypodense on CT and demonstrates heterogeneous enhancement after contrast administration or ringlike enhancement. On MRI, these lesions usually demonstrate hypointensity on T1-weighted images and hyperintensity on T2-weighted images, with a central hyperintense component (necrotic tissue) surrounded by a low-signal-intensity periphery (oedematous stroma with inflammatory cells). Clinical and radiologic findings are not pathognomonic for this benign tumour that can mimic malignant lesions such as the rhabdomyosarcoma, the most common bladder tumour in children.
It represents 20% of all rhabdomyosarcomas. The average age of diagnosis is 4 years; with males more affected (3:1). Clinically, it always presents with macroscopic haematuria, abdominal pain and recurrent urinary infections.
Local aggressive appearance, with extramural growth and early metastasation are frequent aspects.
Cystitis cystica, glandularis or eosinophylic are common chronic reactive inflammatory disorders, more often affecting children. Clinical and radiologic findings can be very similar to those of rhabdomyosarcoma or inflammatory pseudotumour, and usually biopsy is necessary to avoid unnecessary aggressive treatments.

Differential Diagnosis List

Final Diagnosis

Inflammatory pseudotumour of the bladder

URL:	https://www.eurorad.org/case/9089
DOI:	10.1594/EURORAD/CASE.9089
ISSN:	1563-4086