LAUSR

A 76-year-old man presented with significant lower urinary tract symptoms, macroscopic haematuria and recurrent urinary tract infections. Initial investigations were consistent with bladder outlet obstruction secondary to an enlarged prostate. Digital rectal examination revealed a grossly enlarged, benign prostate. His urine peak flow was poor at 8 mL/s and he had a post-void residual of 160 mL. A renal tract ultrasound showed a 150-cc prostate protruding into the bladder (Fig. 1). His prostate-specific antigen level was 1.4 ng/mL and other investigations wereunremarkable.His relevantpasthistory includemyelofibrosis, open cholecystectomy and rivaroxaban therapy for atrial fibrillation. Cystoscopically, there appeared to be a massively enlarged middle lobe of a benign prostate and he underwent a transurethral resection (TUR) of the prostate with 105 g resected. Histopathology showed a high-grade stromal tumour, favouring leiomyosarcoma of the prostate (this diagnosis was later amended following additional staining of the pathological specimen). Positron emission tomography/computed tomography imaging was performed for staging 4 weeks postoperatively, which showed a 4-cm prostatic mass (Fig. 2a) and no evidence of metastatic disease. His urinary symptoms initially improved, but he represented on three occasions with clot retention. On the third presentation, due to his significant suprapubic pain and ongoing haematuria requiring blood transfusion, he was taken emergently to operating theatres where cystoscopy revealed significant obstructive regrowth of the tumour with a large intravesical component. A large debulking TUR of the prostate and bladder tumour was performed 6 weeks after the initial TUR of the prostate, with 150 g resected. He underwent further magnetic resonance imaging for local staging of his disease showing significant regrowth almost completely occupying the bladder despite the second resection (Fig. 2b). He underwent cystoprostatectomy, bilateral pelvic lymphadenectomy and ileal conduit 2 weeks following the second TUR (Fig. 3). Operating time was 5 h and 10 min, and he had an uneventful post-operative course. Histopathology revealed a 16-cm tumour with spindle cells displaying marked nuclear pleomorphism and areas of bizarre multinucleated giant cells. This was reviewed by a specialist soft-tissue tumour pathologist and additional stains performed (myogenin and myoD1) were positive, identifying the cellular differentiation of the tumour as skeletal muscle. The final histopathological diagnosis was a pleomorphic rhabdomyosarcoma of bladder origin infiltrating the deep muscularis propria (pT2) and contiguous involvement of the prostate with clear surgical margins and negative lymph nodes. Fig. 1. Longitudinal view of the bladder on ultrasound showing an enlarged 150-cc prostatic mass (*) protruding into the bladder (arrow).