Decoding Malignant Lung Ground Glass Opacities: A Radiologic-Pathologic Study From Pure to Semi-Solid Lesions

Ground-glass opacities (GGOs) are increasingly detected due to widespread low-dose CT screening for lung cancer. Among them, malignant GGOs (mGGOs) are a clinical challenge. This study aimed to compare the radiological and anatomopathological characteristics of pure and semi-solid mGGOs and to identify radiological predictive factors for consolidation.

A retrospective study was conducted on patients resected due to mGGOs between 2016 and 2023. Patients were classified based on whether initially pure mGGOs remained pure or developed a solid component before surgery. Radiological, pathological, and molecular characteristics were analyzed.

Of 135 patients, 61 (46%) mGGOs became partially solid during surveillance. Semi-solid mGGOs had a higher acinar component (p = 0.038) and larger pathological diameter (20 vs. 18 mm, p = 0.047), while pure mGGOs had a higher lepidic percentage (20% vs. 10%, p = 0.026). STAS and LVI were observed in 25% and 15% of cases. Logistic regression showed pleural contact was protective against consolidation (p = 0.033), while arterial vascularization was predictive of consolidation (p = 0.028). Five-year survival was comparable and satisfactory for both groups (81.7% for pures and 85.5% for semi-solids). Overall, LVI but no STAS was cause of a lower survival expectancy in the entire sample, regardless of consolidation (p = 0.004).

Both pure and semi-solid mGGOs showed precocious pathological and molecular features. Surgical intervention with curative intent, even in pure GGOs, is accompanied by long expected survivals. Vascular features on imaging may help inform surgical decision-making, whereas pathological LVI may have prognostic significance in patients with mGGOs.