Diagnostic contribution of EBUS in Interstitial Lung Desease (excluding Sarcoidosis)

Introduction: The reasons for developing intra-thoracic lymph nodes (LN) in ILDs are varied: simple non-specific inflammatory process, dustiness, infection, neoplasia. Thus, invasive or “minimally invasive” diagnostic exploration, with possible complication, is sometimes necessary. The objective was to study the prevalence of the different cytological diagnoses obtained by EBUS from LN associated with ILD, to describe their computed tomography (CT) and PET-CT features and to determine the predictive factors of the diagnosis. Methods: A retrospective, observational, multicenter study (pneumology departments of Avicenne and Amiens University Hospitals, and St-Quentin Hospital), including 32 patients who underwent EBUS between 2008 and 2017 for LN associated with ILD excluding sarcoidosis (age: 63 ± 14.7 years, men: n = 21, smokers or former smokers: n = 19). Results: LN cytology was normal in 20 cases (62.5%), and showed anthracosis in 8 cases (25%), cancer in 3 cases (9.4%) and non-necrotizing granulomatosis in one case. There was no correlation between cytological diagnoses and CT features. Patients with cancer had a lower number of LN tracer uptake (1.00 ± 0, p = 0.002), and a higher mean SUV (14.36 ± 10, p = 0.041) at PET-CT. In multivariate analysis, no factor was significantly associated with the malignant or benign nature of LN. Conclusion: LN in ILDs appear to be mainly related to the inflammatory process of ILD or to anthracosis. Few items are predictive of malignant LN. In this context, the diagnostic impact of EBUS is important for management of these patients.