Abstract
Background. Lepidic-predominant adenocarcinoma can sometimes mimic pneumonia, and the two conditions are especially difficult to distinguish in patients with combined infection, such as empyema. Case. A previously healthy 45-year-old male presented with a fever and cough, and a chest X-ray revealed bilateral infiltrative shadows with right-sided pleural effusion. Hypoxemia was also present. Thoracentesis performed on admission to the hospital showed the pleural effusion to be empyema. A chest tube was immediately placed, and a course of antibiotics was administered. The therapy ameliorated the patient's fever and inflammatory findings; however, the dyspnea and radiological findings remained unchanged. A combination of infectious disease and lung cancer was suspected, and a bronchoscopic lung biopsy was performed, which led to a final diagnosis of lepidic-predominant adenocarcinoma with an epidermal growth factor receptor mutation. The patient's oxygenation and lung filtration improved after gefitinib therapy. Conclusions. If antibiotic therapy fails to improve pneumonia, it is necessary to distinguish lepidic-type adenocarcinoma of the lung from infectious disease.
