Leiomyoma of the urinary bladder

Clinical History

A 32-year-old previously healthy female developed attacks of suprapubic pain for 1 month and haematuriea for 2 weeks. She had no past history of stone disease, urinary tract infection or surgical intervention.

Imaging Findings

MRI was done on a 1.5 Tesla machine with the following imagining parameters; axial high resolution T2wi (HR-T2wi) (Fig.1&2) (Torso coil, TR/RE 4240/90, FOV=18 cm, Matrix size: 265 X 224, NEX: 4, Slice thickness: 3 mm, Intersection gap: 1), coronal (Fig. 3&4) and sagittal (Fig. 5) T2wi of the pelvis (Torso coil, TR/RE 3000/90, FOV=28 cm, Matrix size: 256 X 219, NEX: 2, Slice thickness: 10 mm, Intersection gap: 2) revealed large intravesical soft tissue mass with minute areas of cystic degeneration inside, this mass is seen arising from the bladder neck away from both ureteric orifices, it is seen arising from the mucosa of the bladder with no evidence of superficial or deep muscles infiltration, stage T1 bladder tumour. This mass was finally diagnosed radiologically as; intravesical mass likely malignant of stage T1.

Discussion

Most bladder tumours are derived from the urothelium. Benign mesenchymal tumours are rare and comprise 1 to 5% of all bladder neoplasms [1]. Most of these tumors are benign and include leiomyoma, neurofibroma. pheochromocytoma. hemangioma. fibroma, nephrogenic adenoma. Inflammatory pseudosarcoma. and rhabdomyoma [2]. Among them, leiomyoma is the most common benign neoplasm, accounting for 0.43% of bladder tumours [1].
About 250 cases of leiomyoma of the bladder have been previously reported in the English language scientific literature [3]. The incidence of leiomyoma of the bladder is approximately three times higher in women than in men [1].
Among the non-invasive imaging modalities, MRI is the modality of choice for imaging the urinary bladder cancer. Multi-planer capabilities and superior soft tissue make this technique a valuable tool for imaging the urinary bladder. In addition, recent advances such as high resolution fast imaging sequences, the use of pelvic phased array coils and contrast agents further improve the imaging quality and thus the diagnostic accuracy for staging urinary bladder carcinoma [4,5].
Non-degenerative leiomyomas are usually visualised on MRI as low-intensity masses both on T1 and T2 weighted sequences with a smooth surface, while degenerative leiomyomas have a heterogeneous signal intensity. A variable pattern of enhancement is observed after the injection of gadolinium: some leiomyomas are homogenously enhanced, while others are not [6,7].
Our patient underwent cystoscopic transuretheral resection (TURBT) of nodular soft tissue growth. Post operative histopathology (Fig.6) was leiomyoma.
We must keep in mind that not all the urinary bladder tumors all malignant and no definite criteria of malignancy except in the aggressive infiltration to the bladder wall and pelvic lymphadenopathy.

Differential Diagnosis List

Final Diagnosis

Leiomyoma of the urinary bladder

URL:	https://eurorad.org/case/9699
DOI:	10.1594/EURORAD/CASE.9699
ISSN:	1563-4086