Features for Predicting Absorbable Pulmonary Solid Nodules as Depicted on Thin-Section Computed Tomography

Abstract

Purpose To investigate the clinical and computed tomography (CT) characteristics of absorbable pulmonary solid nodules (PSNs) and to clarify CT features for distinguishing absorbable PSNs from malignant ones. Materials and Methods From January 2015 to February 2021, a total of 316 patients with 348 PSNs (171 absorbable and 177 size-matched malignant) were retrospectively enrolled. Their clinical and CT data were analyzed and compared to determine CT features for predicting absorbable PSNs. Results Between absorbable and malignant PSNs, there were significant differences in patients’ age, lesions’ locations, shapes, homogeneity, borders, distance from the pleura, vacuoles, air bronchograms, lobulation, spiculation, halo sign, multiple concomitant nodules and pleural indentation (each P < 0.05). Multivariate analysis revealed that the independent predictors of absorbable PSNs were the following: patient age ≤55 years (OR, 2.660; 95% CI, 1.432–4.942; P = 0.002), homogeneous density (OR, 2.487; 95% CI, 1.107–5.590; P = 0.027), ill-defined border (OR, 5.445; 95% CI, 1.661–17.846; P = 0.005), halo sign (OR, 3.135; 95% CI, 1.154–8.513; P = 0.025), multiple concomitant nodules (OR, 8.700; 95% CI, 4.401–17.197; P <0.001), and abutting pleura (OR, 3.759; 95% CI, 1.407–10.044; P = 0.008). The indicators for malignant PSNs were the following: lobulation (OR, 3.904; 95% CI, 1.956–7.791; P <0.001), spiculation (OR, 4.980; 95% CI, 2.202–11.266, P <0.001), and pleural indentation (OR, 4.514; 95% CI, 1.223–16.666; P = 0.024). Conclusion In patients younger than 55 years, PSNs with homogeneous density, ill-defined border, halo sign, multiple concomitant nodules, and abutting pleura should be highly suspected as absorbable ones.

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

“…For clinical characteristics, this study showed that no significant difference was observed in patient’s age between the two groups. Previous research has shown that patients with lung cancer tend to be older than those with inflammatory lesions, possibly because increasing age comes with increasing incidence of malignancy due to decreased immune function and added total exposure to carcinogens; 16 , 17 however, those results are not consistent with our findings. The conflicting results among studies may be related to differences in sample size and study design.…”

“…These findings could likely be attributed to differences in the pathological basis between inflammatory and malignant SSNs. Pathologically, GGO in inflammatory SSNs was associated with exudation filling in the alveolar space, which tended to result in an irregular shape, vague edge, and a low density of GGO areas on CT. 17 , 21 Contrastingly, GGO in malignant SSNs was related to minimal invasion of tumor cells along pre-existing alveolar structures but not completely filling the alveolar space, which might easily cause a regular shape, clear edge, and a relatively high density of GGO areas on CT. Previous research found that a regular shape and a well-defined-but-coarse interface were more common in malignant nodules than those in inflammatory ones, 22 , 23 with our results showing the same.…”

Clinical and Computed Tomography Characteristics of Solitary Pulmonary Nodules Caused by Fungi: A Comparative Study

“… 25 Pathologically, it is caused by accumulation of inflammatory cells and exudation in the central zone and spreading to the surrounding lung tissue. 26 In the present study, both the fungal nodules and lung cancers had this sign but which was more common in the former and had significantly different CT characteristics between them. The HS in fungal nodules was usually annular and ill-defined, while all of that in lung cancers was partial and well-defined, which was consistent with previous results.…”

“…The HS in fungal nodules was usually annular and ill-defined, while all of that in lung cancers was partial and well-defined, which was consistent with previous results. 26 , 27 Therefore, the HS should be seen as another key radiological indicator in differentiating them; however, its boundary and scope should be further evaluated before making diagnosis.…”

Quantitative evaluation of density variability in the lesion–lung boundary zone to differentiate pulmonary subsolid nodules

“…Normally, most benign SSNs are caused by inflammation, which usually results in a series of pathophysiological changes, such as increased vascular permeability, inflammatory cell infiltration, and serous exudation ( 21 , 22 ). When inflammatory exudation peripherally diffuses through the alveolar pore, the peripheral lung tissues around nodules contain more cells and/or liquid and show an increased density ( 14 , 23 ). Therefore, the density difference between SSNs and adjacent lung tissues reduces.…”