A chest wall pulsating mass.

A 34-year-old HIV-positive man with intravenous drug addiction presented with a 2-week history of fever and a pulsatile presternal mass; 2 weeks prior he had suffered a traumatic sternal fracture. The CT scan showed a bulky abscess with presternal and retrosternal extension that contacted the heart (which explained its pulsatile effect) and pulmonary necrotising lesions. Drainage of the thoracic wall abscess was performed, and antibiotics (flucloxacillin plus gentamicin) were started on the presumption of staphylococcal bacteraemia given the patient's intravenous drug habit. Blood cultures and culture of the aspirated pus confirmed growth of methicillin-sensitive Staphylococcus aureus; transoesophageal echocardiography showed endocarditis of the tricuspid valve. We therefore assumed pulmonary septic embolisation from right-sided endocarditis and acute sternal osteomyelitis, and the patient was treated for 6 weeks with clinical resolution. 2015 BMJ Publishing Group Ltd.