Presentation
History of urinary retention, no pain or palpable mass.
Patient Data
Heterogenous mass at the neck of the bladder with post void residual volume of >250 mL. In real time this lesion did not communicate with the deep pelvic structures and was in the location of the superior vagina.
Posterior to the pubic symphysis there is a soft tissue density non-enhancing structure that indents the inferior bladder. This corresponds to the lesion noted on the ultrasound. There is significant osteophyte formation at the pubic symphysis with hypertrophy of the fibrocartilage disc.
A heterogeneously T2 hyperintense, T1 low signal focus is noted arising from the posterior pubic symphysis in continuity with the symphocele cartilage. There is no associated diffusion restriction. There is mild local mass effect on the bladder which is displaced posteriorly. The overlying bladder wall does not appear thickened.
Case Discussion
This is a rare cause of renal tract obstruction, predominantly occurring in female patients. It can present as a vaginal mass or with renal tract obstruction and is thought to be due to cystic degeneration of a cartilaginous cyst arising from the pubic symphysis.
Decompression/aspiration or surgical removal of these have been trialed and been successful in symptomatic patients.