Abstract
CT scans of 36 patients with lung cancer, which showed possible contact with the pleural surface, were reviewed retrospectively, based on the surgical-histological evidence. The CT features of the primary lesions included: the angle and amount of contact with pleural surface, the long dimension, area of contact with pleural surface, and associated pleural thickening along with the extrapleural fat plane. From these data, more significant CT findings of tumor invasion to the parietal pleura (Stage p3) were summarized as follows: 1) obtuse angle, 2) 3 cm or more contact with pleural surface (10 cm2 or more areas), 3) associated pleural thickening, and 4) loss of the extrapleural fat plane. Statistically, in spite of showing a high negative predictive value in each item (84-93%), the positive predictive value still remained unsatisfactory (48-56%). However, specificity, calculated by combining all items using a scoring method (1 point for each item), resulted in such improvement that 71% of the cases given 3 points or more were in Stage p3 while 91% of those given 2 points or less were in Stage p2 or lower. Another histology-oriented investigation suggested that adenocarcinoma was more invasive than squamous cell carcinoma.
