Granulomatosis with polyangiitis (GPA) is an autoimmune systemic vasculitic disease and is a rare cause of prostatitis. This illustrates a rare case of granulomatous prostatitis secondary to unrecognised GPA requiring multiple surgical interventions. There have been no reported cases of rapidly recurrent prostatic inflammation requiring multiple endoscopic interventions within 12 months within this setting. The rarity of this pathology, the impact of delayed diagnosis and the systemic nature of this disease are emphasised.

Comprehensive literature review revealed only 26 cases of prostatic GPA, only two of which required surgery for urinary retention.

A 75-year-old patient presented with lower urinary tract symptoms (LUTS). Renal ultrasound revealed a prostate volume of 54cc. A flow rate was performed with a peak flow of 9mls/second. A provisional diagnosis of benign prostatic hyperplasia was made. Medical management was commenced however the patient required an indwelling catheter (IDC) for acute urinary retention (AUR) shortly after. The patient subsequently underwent a trans-urethral resection of the prostate (TURP). An oedematous hyper vascular prostate was noted and 26cc of tissue was resected. Post operative histology revealed widespread focally necrotising suppurative granulomatous inflammation intermixed with benign prostatic tissue. Despite a period of 8 weeks IDC free, the patient once more experienced AUR and consequently underwent cystoscopy. Prostatic swelling and vascular nodular regrowth were identified. An additional TURP was performed. Post operative pathology revealed the same histological findings. The patient was then referred to the rheumatology team with worsening dyspnoea and new sinusitis. Bronchoscopic and nasopharyngeal biopsies revealed systemic necrotising granulomatous inflammation. A diagnosis of systemic granulomatous polyangiitis was made and the patient was commenced on prednisolone and rituximab quickly improving their LUTS.

GPA rarely involves the prostate. More rarely, localised prostatic inflammation may result in urinary retention. Early recognition and immunosuppression may minimise the need for surgical intervention. The rarity of this pathology, the impact of delayed diagnosis and the systemic nature of this disease are emphasised in this report. GPA should always be considered in patients with unexplained prostatitis and systemic evidence of inflammation.