Pyogenic psoas abscess: clinical profiles, imaging features, and outcomes in a retrospective single-center study of 32 cases

Psoas abscess is a rare, complex condition often associated with various underlying diseases and nonspecific clinical signs, which can delay diagnosis and increase mortality. This study aimed to evaluate the clinical, epidemiological, and radiological characteristics, as well as treatment outcomes, of patients diagnosed with psoas abscess. This retrospective study included patients with psoas abscess treated at Ankara Bilkent City Hospital between February 2019 and February 2022. Epidemiological data, comorbidities, microorganisms identified in abscess or blood cultures, imaging findings, and treatment outcomes were analyzed. Abscesses without an identifiable infectious source were classified as primary, while those secondary to nearby infections were classified as secondary. Statistical analysis was performed using SPSS 20.0. Thirty-two patients were included: 9 with primary and 23 with secondary abscesses. The mean age was 60.5 ± 14.6 years, and 62.5% were male. Predisposing factors included prior surgery (31%), vertebral osteomyelitis (25%), trauma (12.5%), and foreign bodies (12.5%). Common symptoms were back pain (78.1%), radiating leg pain (50%), fever (53.1%), and chills (62.5%), with symptom duration exceeding 15 days in 46.9% of cases. Primary abscesses were often associated with immunosuppression (44.4%), whereas secondary abscesses most frequently involved musculoskeletal (82.6%) or cardiovascular systems (26%). Among pathogens isolated from abscess cultures, Staphylococcus aureus was the most frequently identified organism, followed by Streptococcus spp. and Enterococcus spp. Brucellosis and tuberculosis were identified in selected patients based on serological or immunological criteria. Half of the patients underwent percutaneous drainage plus antibiotics; others received either antibiotics alone (25%) or drainage with surgery (18%). The median duration of antibiotic therapy was 48 days. Complete cure was achieved in 46.9% of patients, 40.6% recovered with sequelae, and 12.5% died. Recurrence occurred in ten patients. Psoas abscess remains a rare but serious condition with diverse etiologies. Prompt recognition and prolonged treatment are critical, and S. aureus is the most frequently isolated pathogen.