1448. Prostate Abscess: Clinical Features, Management, and Outcomes of a “Stealth” Infection: A Case Series

BACKGROUND: Prostate abscess (PA) is uncommon and the diagnosis is often delayed or missed. Traditionally, PA has resulted from acute prostatitis or ascending genitourinary (GU) infection due to gram-negative bacilli but S. aureus is an emerging cause. METHODS: A retrospective review of all adult patients admitted with an ICD-9 or -10 diagnosis of PA between January 2013 and July 2018 was conducted. Inclusion criteria included age ≥18 years, a compatible GU infection syndrome, and imaging consistent with PA. RESULTS: Twenty-two patients with PA were identified. The median age was 57 years. Five patients (22.7%) were immunosuppressed and 11 (50%) had diabetes. The median Charlson Comorbidity Index was 2. No patient had a prior history of PA but 3 patients had a past diagnosis of prostatitis. Only 1 patient had GU instrumentation in the preceding 6 weeks and no patient had an indwelling urethral catheter. Fever (59%), dysuria (49%), and urinary retention (32%) were the most common presenting symptoms. Only 7/18 (39%) patients had a tender prostate on examination; fluctuance was not described. Pelvic CT revealed PAs in all patients; 14 (64%) were solitary and 16 (73%) were >2 cm in greatest diameter. The median abscess size was 3.2 cm. Urine cultures were positive in 11/18 (61%) patients with 6/11 (55%) growing S. aureus (MRSA 3); 9/16 (56%) patients had positive blood cultures (S. aureus 7 with MRSA 3) and 5/5 had positive PA cultures (S. aureus 1). Nine patients (41%) were managed with antibiotics alone whereas 13 (59%) underwent abscess drainage. The median duration of antibiotic therapy was 34.5 days. All-cause mortality at 4 weeks was 9.1%. No relapses were documented at 6 months. When comparing patients with S. aureus PA to those with other causes, S. aureus patients more often had diabetes (86% vs. 33%, P = 0.06) and a longer median duration of antibiotic therapy (35 days vs. 31 days, P = 0.04) but age, abscess size, and mortality did not differ between groups. CONCLUSION: PA is relatively uncommon and may be difficult to distinguish clinically from acute prostatitis. CT is critical to an accurate diagnosis. Optimal management usually requires both antibiotics and drainage. Given the frequent occurrence of S. aureus as a cause, coverage for MRSA should be a component of empiric treatment for PA. DISCLOSURES: All authors: No reported disclosures.