Pitfalls in CT evaluation of chest wall invasion by lung cancer

Computed tomography in a patient with a peripheral lung cancer in the right upper lobe revealed obliteration of the extrapleural fat and direct connection of the tumor with an intercostal soft tissue mass of similar density. The findings were suggestive of chest wall invasion by the cancer which was, however, proven to be false after en bloc resection of the tumor and the contiguous chest wall. Such a diagnostic pitfall could be avoided if special attention were paid to the asymmetry of the CT image at the level of upper thoracic outlet due to improper positioning of the patient.