Significance and prognostication of mediastinal lymph node enlargement on chest computed tomography among adult Indigenous Australians.

Abstract

INTRODUCTION: There is a lack of data on chest computed tomography (CT) findings on mediastinal lymph node enlargement (MLE), including normal size threshold of less than 10 or 15 mm for MLE among Indigenous Australians. In this study, we assessed the significance and the applicability of the current guidelines for the threshold for abnormal MLE among adult Indigenous Australians. METHODS: Patients who underwent chest CT between 2012 and 2020 among those referred to undergo lung function test (spirometry) were assessed for the presence of MLE which were classified as Group A (no measurable nodes), Group B (<10 mm), Group C (≥10 to 14.99 mm) and Group D (≥15 mm). RESULTS: Of the total 67 patients identified to have MLE, 49 patients had at least two CT scans available for assessment over a median follow-up period of 101.3 weeks (IQR: 62.4, 235.6) and were included in the analysis. Evidence of chronic lung disease was common, with a significant proportion demonstrating either COPD or bronchiectasis and a high proportion with smoking history (93%). During the first CT scan, 34/49 (69%) had >10 mm nodes, of which 12/34 (35%) reduced in size, 22/34 (65%) remained stable, and 3/34 (9%) had malignancy on follow-up. CONCLUSION: Despite most patients demonstrating the presence of significant MLE with varying size and in most >10 mm, the majority remain stable or benign in nature and only a minor proportion showed evidence of lung malignancy. Further prospective studies are needed in the characterisation of MLE among Indigenous patients.