[Two cases of localized organizing pneumonia simulating lung cancer]

Localized organizing pneumonia is one of the benign conditions which must be differentiated from lung cancer. We have reported two cases of localized organizing pneumonia diagnosed by histological study of surgical specimens. Two cases were initially regarded as lung cancer, because the symptoms of respiratory tract infection were not remarkable and initial roentgenographic findings revealed a tumor-like shadow. Diagnostic thoracoscopy which was less invasive upon a patient were very useful in differentiating organizing pneumonia from lung cancer.