Diverticulum of the bladder simulating ovarian cyst: pitfalls in the differential diagnosis.

A 69-year-old Para 2 attended the outpatient department for an ultrasound scan of the pelvis. Her medical history revealed 3 lower urinary tract infections in the preceding months. Vaginal ultrasound of the pelvis showed a multilocular cyst measuring 17 x 17 x 17 cm, apparently originating from one of the adnexa and ascites. Coronal (A) and transverse CT scan (B) of the pelvis demonstrates a cystic mass, initially interpreted as an adnexal mass, suspicious for ovarian malignancy. There were septations within the mass (arrows). Retrospectively, this scan shows the bladder neck (triangles), and bladder diverticulum (A) connected to the bladder (B).