Obliteration of the pulmonary vein in lung cancer: Significance in assessing local extent with CT

Purpose: The purpose of this study was to evaluate the significance of obliteration of the pulmonary vein in assessing local extent of lung cancer with CT, particularly in regard to intrapericardial extension of tumor through the vein. Method: Preoperative CT scans of 325 patients, who underwent thoracotomy for primary lung cancer, were reviewed. Among them, CT scans of 19 patients showed obliteration of the pulmonary vein up to its entrance into the left atrium, without filling defect in the left atrium. Surgical records of these patients were then reviewed to investigate the extent of tumor growth through the pulmonary vein, with particular emphasis on intrapericardial extension. Results: The surgical records revealed extension of tumor through the pulmonary vein beyond the pericardial reflection in 14 of 19 patients. In 10 patients showing obliteration of either the left or the right superior pulmonary vein, all tumors extended beyond the pericardial reflection (100%). Intrapericardial extension occurred in four of nine patients showing obliteration of either the left or the right inferior pulmonary vein (44%). The difference was statistically significant (p < 0.05). Conclusion: When assessing local extent of lung cancer with CT, obliteration of the superior pulmonary vein is a highly suggestive finding for intrapericardial extension of tumor through the pulmonary vein. On the contrary, obliteration of the inferior pulmonary vein is believed to be a less reliable finding for intrapericardial extension of lung cancer.