Detection of Subpubic Tumor Causing Bladder Outlet Obstruction by 3-D-Perineal-Ultrasound

Abstract

This case report shows that 3D-perineal ultrasound can be superior to clinical examination and routine 2D-perineal ultrasound in the detection of an unusual subpubic tumor. A 73-year-old female patient was referred to our urogynecological outpatient unit complaining of over-active bladder symptoms and voiding dysfunction for 3 years. Gynecological examination found no signs of pelvic organ prolapse or abnormality in the vaginal cavity. Routine 2D-perineal ultrasound showed substantial residual urine (ca. 300-ml on catheter) and limited bladder neck mobility, but no signs of pelvic organ prolapse. Use of standardized 3D-perineal ultrasound revealed a 24-×-26-×-32-mm spherical, hypoechoic tumor below the pubic symphysis between the distal urethra and the pubic bones. This structure was mistaken for the pubic symphysis in the midline on 2D-ultrasound performed earlier. At surgery, the tumor was completely excised through a vaginal incision between the urethra and the pubic symphysis. After an uneventful postoperative recovery the patient developed de-novo stress urinary incontinence, which was corrected successfully by the insertion of a retropubic tension-free suburethral sling after an interval of 8 weeks. After a further follow-up of 8 weeks the patient reported well-being, urinary continence and no voiding dysfunction; no abnormalities were found on examination. In conclusion, 3D-perineal ultrasound is a useful additional tool for the diagnostic workup of bladder outlet obstruction.