Abstract: Objective To investigate the thin-section CT signs of peripheral non-small cell lung cancer below 3 cm with solid nodule, and to improve the accuracy of its histopathological type prediction. Methods We retrospectively analyzed the 218 cases of solid nodules 3cm or less with non-small cell lung cancer (including 76 cases of squamous cell carcinoma, 142 cases of adenocarcinoma) confirmed by surgical pathology. The patient's clinical pathology included gender, age, and pathological type of tumor, as well as location, diameter, morphology, marginal features, and enhancement of nodules. The measurement data were expressed as x ± s. The count data were expressed as a percentage. Chi-square test was used to compare differences between groups of signs. Results There was a statistically significant difference in the prevalence of p-SqCC and adenocarcinoma solid nodules between men and women. The p-SqCC and adenocarcinoma solid nodules at the focal necrosis, air bronchogram sign, vacuolar sign, burr sign, pleura indentation, and enhancement pattern were statistically significant (P＜0.05). There was no statistical difference in nodule shape, lobulated sign, hole sign, and bronchial vascular bundle sign. Conclusion The specificity of diagnosis for adenocarcinoma solid nodules is 89.7% based on air bronchogram sign, bronchus encapsulated air sign, pleura indentation, and short burr sign. Focal necrosis is specific for p-SqCC diagnosis. Thin-section CT signs have certain value in the differential diagnosis of peripheral adenocarcinoma solid nodules and p-SqCC.

Key words: Peripheral lung Squamous cell Carcinoma（p-SqCC）, Aenocarcinoma, Tomography,Computed, clinicopathologic characteristics