Ground glass opacity: can we correlate radiological and histological features to plan clinical decision making?

Background: The spectrum of ground glass opacity (GGO) is a diagnostic and clinical management quandary. The role of computed tomographic scans in detecting malignant GGO has inter-observer variability. Pure GGO have been traditionally thought to be predominantly benign in nature and has long volume doubling times. This study was undertaken to correlate the findings of radiology and histology of ground glass opacities at our institute.

Methods: This study is a retrospective observational study of patients who underwent lung resection surgery for radiology proven ground glass opacities between January 2010 and December 2018. A total of 115 patients were included in the study based on inclusion and exclusion criteria and were analysed.

Results: The patients were divided into two groups; pure GGO (n = 50), mixed GGO (n = 65). The pathological tumour size was ≤ 2 cm in 51% of the patients and 27 patients had the size between 2.1 and 3.0 cm. The predominant histopathologic feature was lepidic predominance in 54 patients followed by 24 patients with acinar predominance. Among patients with radiological tumour size of ≤ 2 cm, pure GGO was present in 48% of the patients. Among patients with pure GGO, 96% of the patients had no solid component. 44 patients had only single CT scan before proceeding to surgery. All these patients had mixed GGO.

Conclusion: Our study concludes pure GGOs, though lacking solid component have a high propensity to be malignant. The role of repeated CT surveillance in this context without offering curative surgery may be questionable.