This is a 29-year-old woman who underwent a follow-up pelvic ultrasound examination after laparoscopic tubal ligation. During the study, a 20 mm tumour was detected on the right lateral aspect of the bladder, well defined and hypoechoic. The patient had no micturition symptoms, as she mentioned in the subsequent interrogation.

Intravenous urography was performed, which did not detect any alteration of the upper urinary tract. The cystogram showed a rounded, smooth-surfaced repletion defect located in the right bladder wall. Blood and urine tests were within normal limits. The patient underwent cystoscopy, which revealed the presence of a "hump-shaped" tumour with a smooth surface and preserved mucosa on the right lateral aspect of the bladder, immediately above and in front of the ipsilateral ureteral meatus.

With the presumptive diagnosis of bladder leiomyoma, transurethral resection of the tumour was performed. The resected fragments had a whitish, solid and compact appearance, similar to that of a prostatic adenoma, with little bleeding.

The material obtained from the transurethral resection consisted of a proliferation of spindle cells with elongated cytoplasm, like the nucleus, and slightly eosinophilic. No mitoses or atypia were observed. Immunohistochemistry showed positivity for muscle-specific actin (DAKO, clone HHF35 ) in the proliferating cells.

Three months after transurethral resection, a control cystoscopy was performed, showing a raised calcareous plaque over the area of previous resection, compatible with encrusting cystopathy, which was treated by transurethral resection of this and leiomyomatous debris and subsequent urinary acidification.