CT features of intrapulmonary lymph nodes: a comparative study with pathology

Abstract

Objective To explore the CT features and pathology of intrapulmonary lymph nodes (IPLNs), so as to improve the understanding and diagnosis of IPLNs. Methods A total of 38 patients (49 IPLNs) who were confirmed by the surgery and pathology were retrospectively analyzed, including 21 males and 17 females with a mean age of (56±8) years. All the patients underwent MSCT scan and 1.0 mm thin layer reconstruction before surgery. Double-blind method was used to analyze CT signs and the corresponding histopathological changes were compared. Results (1) Location: all IPLNs were located below the level of tracheal carina with 17 were on the left lung, and 32 were on the right lung. (2) Shape: 34 IPLNs were round, 15 were triangular or prism and so on. (3) Size: the maximum diameter of IPLNs ranged from 0.26 to 1.28 cm (0.66±0.23 cm), of which 45 cases were ≤ 1.0 cm. (4) Quantity: 28 IPLNs were solitary and 10 were multiple. (5) Density: All 48 IPLNs were solid nodules with a median CT value of 43 HU (range from 19 to 106 HU), and there were no calcification, vacuoles and air bronchial signs were showed. (6) Margin and pleura: all the 48 IPLNs boundaries were clear and smooth, and 45 pieces were less than 1.0 cm from the pleura, of which 20 were close to the pleura or inter-lobar fissure. (7) Other: no satellite focal , pleural depression syndrome, and vascular bundle sign were showed;22 peripheral fine lines of IPLNs were visible. (8) Pathology: IPLNs were dark brown or gray-black nodules with well-defined borders, coated, tough, hard, and carbon deposition could be seen in most cases. Conclusion IPLNs are benign nodules in the lung, which have certain CT features and typical pathological changes. Based on the CT performance and characteristics, it is helpful to make correct diagnosis of IPLNs before operation. Key words: Intrapulmonary lymph nodes; Tomography, X-ray computed; Pathology