Pulmonary Benign Ground-Glass Nodules: CT Features and Pathological Findings

Abstract

Background: Some pulmonary ground-glass nodules (GGNs) are benign and frequently misdiagnosed due to lack of understanding of their CT characteristics. This study aimed to reveal the CT features and corresponding pathological findings of pulmonary benign GGNs to help improve diagnostic accuracy. Patients and Methods: From March 2016 to October 2019, patients with benign GGNs confirmed by operation or follow-up were enrolled retrospectively. According to overall CT manifestations, GGNs were classified into three types: I, GGO with internal high-attenuation zone; II, nodules lying on adjacent blood vessels; and other type, lesions without obvious common characteristics. CT features and pathological findings of each nodule type were evaluated. Results: Among the 40 type I, 25 type II, and 14 other type GGNs, 24 (60.0%), 19 (76.0%), and 10 (71.4%) nodules were resected, respectively. Type I GGNs were usually irregular (25 of 40, 62.5%) with only one high-attenuation zone (38 of 40, 95.0%) (main pathological components: thickened alveolar walls with inflammatory cells, fibrous tissue, and exudation), which was usually centric (24 of 40, 60.0%), having blurred margin (38 of 40, 95.0%), and connecting to blood vessels (32 of 40, 80.0%). The peripheral GGO (main pathological component: a small amount of inflammatory cell infiltration with fibrous tissue proliferation) was usually ill-defined (28 of 40, 70.0%). Type II GGNs (main pathological components: focal interstitial fibrosis with or without inflammatory cell infiltration) lying on adjacent vessel branches were usually irregular (19 of 25, 76.0%) and well defined (16 of 25, 64.0%) but showed coarse margins (15 of 16, 93.8%). Other type GGNs had various CT manifestations but their pathological findings were similar to that of type II. Conclusion: For subsolid nodules with CT features manifested in type I or II GGNs, follow-up should be firstly considered in further management.

Differential Diagnosis of Nonabsorbable Inflammatory and Malignant Subsolid Nodules with a Solid Component ≤5 mm

“…Unlike inflammatory PSNs, we found that the solid component in malignant PSNs predominantly appeared as an irregular shape with a scattered or eccentric distribution, which was consistent with previous results. 25–28 We also found that the intra-nodular vessel sign which could be evaluated only in SSNs was frequently observed in both groups, which was in agreement with the findings of Gao et al 3 and Fu et al 29 who showed that intra-nodular vessels can be observed in both inflammatory and malignant nodules. Furthermore, Gao et al 3 , 30 indicated that abnormal changes of the blood vessels passing through the nodules are highly suggestive of malignancy.…”

Diagnosis of Benign and Malignant Pulmonary Ground-Glass Nodules Using Computed Tomography Radiomics Parameters

“…The extraction of radiomics parameters was set as follows: image resampling parameters: 2 × 2 × 2 and binWidth: 64. A total of 47 parameters were extracted, including First Order Statistics, 10 Shape, 5 Gray Level Cooccurrence Matrix, 7 Gray Level Run Length Matrix, 11 Gray Level Size Zone Matrix, 11 and Neighboring Gray Tone Difference Matrix. 3…”

Adding predictive and diagnostic values of pulmonary ground-glass nodules on lung cancer via novel non-invasive tests

“…The characterization of CT features of benign nodules was reported in a recent retrospective study on 79 patients with GGNs. Some common CT manifestations were identified, including a regular or irregular nodule with an isolated, blurred internal high-attenuation zone connecting to the blood vessels, or a nodule abutting but not surrounding blood vessels, suggesting that follow-up should be firstly considered for GGNs with these characteristics for a higher likelihood of benignity ( 17 ).…”

“…Most guidelines highly recommend an imaging reassessment within 3 months’ time after first detection of GGN with a size above 10 mm, while a reassessment within 6–12 months’ time is recommended for GGN above 5 mm. This is because mean resolve time of transient GGNs appears to be 4.8 months and most GGNs disappeared within 3 months ( 17 ). The Lung-RADS recommended that the strategy for follow-up of pGGN depends on the size of the nodules.…”