THE DIAGNOSTIC-ACCURACY OF A SOLITARY PULMONARY NODULE, USING THIN-SECTION HIGH-RESOLUTION CT - A SOLITARY PULMONARY NODULE BY HRCT

A solitary pulmonary nodule (SPN) less than 2 cm in diameter of 60 pat ients was evaluated with thin-section, high-resolution computed tomogr aphy (HRCT). The presence of an irregular margin, spiculation, converg ence of the surrounding structure, an air bronchogram and the involvem ent of more than 3 vessels was observed more frequently in malignant n odules than in benign nodules. When one point was given for each findi ng, the mean total scores of each histologic type were as follows; ade nocarcinoma; 2.7, squamous cell carcinoma; 2.5, benign tumor; 0.3, tub erculosis; 1.3, pneumonia; 2.0. When SPNs were classified by the total scores, the SPNs with higher scores (greater than or equal to 3) incl uded 18 of 33 (56%) malignant lesions and only 2 of 28 (7%) benign les ions. This means that sensitivity and specificity in the diagnosis of malignancy in the SPNs with high scores were 56% and 93%, respectively , These observations suggest that SPNs with a score higher than 3 poin ts would be highly suspicious for malignancy but the number of such SP Ns is rather limited. Therefore, more sophisticated methods may be nec essary to better differentiate between malignant and benign SPNs.