[Lung abscess which needed to be distinguished from lung cancer; report of a case]

Differential diagnosis of lung abscess from lung cancer is sometimes difficult.

In February 2009, a 57-year-old man consulted our hospital complaining of bloody sputum. Chest computed tomography (CT) demonstrated a 2.5 cm nodule with pleural indentation, spicula and vascular involvement in the right S(3). Bronchofiberscope could not establish a definitive diagnosis. Blood test showed no abnormality. Three months later, progression of the nodule to the adjacent middle lobe was demonstrated by follow-up CT, and F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) showed isotope accumulation in the nodule and hilar lymph node. A diagnosis of lung cancer was suspected and surgery was performed. The diagnosis of possible lung cancer was made by needle biopsy, and the patient underwent right upper lobectomy and partial resection of middle lobe with standard nodal dissection. The final pathological diagnosis was lung abscess.

Lung abscess must be kept in mind as a possible differential diagnosis when abnormal shadow suspected of lung cancer is observed.