[Mycobacterium avium pneumonia in an HIV negative patient].

A 79-year-old patient was admitted with fever and shortness of breath. His medical history included treatment for lung cancer 3 years previously. The patient's clinical and radiological status remained unchanged despite antibiotic treatment for pneumonia. No infectious pathogen could be identified. Treatment with systemic steroids for suspected cryptogenic organizing pneumonitis (COP) was started. Following steroid treatment the patient's shortness of breath ameliorated and C-reactive protein was normal. Three weeks after admission Mycobacterium avium complex (MAC) grew in sputa cultures and therefore a diagnosis of MAC pneumonia was made.