Empyema necessitans with osteomyelitis of fifth rib due to Nocardia farcinica: a case report

BACKGROUND: Empyema necessitans is a rare pulmonary condition described as the presence of pus in the pleural cavity with insidious extension into the surrounding soft tissue. The common microbial aetiology of empyema necessitans is tuberculosis. Nocardiosis a cause of empyema necessitans is rarely described in the literature. We herein present a case of an 80-year-old male with empyema necessitans with osteomyelitis of rib caused by Nocardia farcinica. CASE PRESENTATION: An 80-year-old male presented with complaints of soft swelling on the left lower posterior chest wall associated with dry cough and breathlessness on exertion. Computed Tomography (CT) thorax demonstrated empyema necessitans with features of left fifth rib osteomyelitis. Radiological guided aspiration of the chest wall collection revealed Nocardia species and surgical drainage of abscess was performed. Matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-TOF-MS) identified the isolate as Nocardia farcinica. He was treated with three-drug regimen: Trimethoprim-sulfamethoxazole, amikacin and ceftriaxone for 2 weeks. After showing improvement patient was discharged and advised to take oral Trimethoprim-sulfamethoxazole for the next 6 months with periodic follow-up. CONCLUSIONS: As our case demonstrates, the possibility of invasive Nocardiosis should not be overlooked even in immunocompetent patients. Clinicians should aware of this rare entity while treating patients with empyema necessitans.