Empyema necessitans presenting as a chest wall abscess managed with minimally invasive drainage

A female patient in her late 60s presented with a painful right lower chest wall swelling. Examination revealed a fluctuant subcutaneous collection, and CT imaging demonstrated a pleurocutaneous tract connecting the collection to a small pleural cavity locule, consistent with empyema necessitans. Historical imaging from 15 years earlier showed pleural calcification at the same site, suggesting a chronically abnormal pleural space predisposing to this presentation. Aspiration of the collection yielded frank pus, although cultures were negative. A 10 Fr non-tunnelled pigtail catheter was inserted into the subcutaneous collection, draining 100 mL before removal 48 hours later. She completed 4 weeks of co-amoxiclav. A subsequent wound swab grew Staphylococcus aureus Serial follow-up demonstrated gradual radiological improvement, with full cutaneous healing by 4 months and no residual pleural collection on chest radiograph at 5 months. This case highlights the variable microbiology, diagnostic challenges and favourable outcomes of minimally invasive management.