A pulmonary abscess, beware of lung cancer!

A pulmonary abscess is defined as necrosis of the pulmonary parenchym caused by microbial infections. The most common organisms are anaerobe bacteria. Local conditions, host resistance and infecting agents all play a role in the formation of pulmonary abscesses. An underlying endobronchial obstructing lung cancer predisposes for the development of a pulmonary abscess. The diagnosis of lung cancer can often be made with computed tomography (CT) of the chest combined with bronchoscopy and cytological analysis of the abscess fluid. We present two patients with a pulmonary abscess caused by an underlying lung cancer. Although in both cases the differential diagnosis was malignancy at first presentation, the diagnosis could not be made definitively prior to surgery, despite intensive investigations with even CT guided biopsies and mediastinoscopy.