Primary carcinoma of the lung overlooked at CT: Analysis of findings in 14 patients

PURPOSE: To describe the appearances of overlooked lung cancer at computed tomographic (CT) examination and to analyze the reasons for failure to diagnose these lesions. MATERIALS AND METHODS: Fourteen patients with 15 overlooked lung cancers were identified by radiologists at three institutions. Location, shape, and cell type of each cancer were reviewed, and other relevant findings of CT examinations were assessed. RESULTS: The missed tumors manifested as endobronchial lesion (n = 10), solitary parenchymal nodule (n = 2), area of focal peripheral airspace disease (n = 2), or pleural-based thickening (n = 1). Eleven (73%) of the 15 lesions were located in a lower lobe. In six (43%) of 14 patients, major distracting findings were present elsewhere in the thorax. CONCLUSION: Endobronchial location and lower lobe predominance were the most common characteristics of overlooked lung cancer at CT. The presence of unrelated major abnormalities at CT may also have contributed to failure to diagnose the tumor.