Eosinophilic globules in bronchoalveolar lavage fluid of patients with systemic sclerosis-related interstitial lung disease: a diagnostically useful, previously unreported finding in a retrospective and prospective study, including differential diagnosis with other idiopathic and secondary interstitial lung diseases

Abstract

Bronchoalveolar lavage (BAL) is a minimally invasive method possibly representing a diagnostic tool in the evaluation of interstitial lung diseases (ILDs) of different causes. We first describe herein the morphologic, histochemical, and immunohistochemical features of previously unreported eosinophilic globular deposits of acellular amorphous material of uncertain nature in a relatively large series of 227 BAL samples obtained from patients with various ILDs. Overall, eosinophilic globules were detected in 18 cases (7.9%), 16 of which were in patients with systemic sclerosis (SSc)-related ILD (16/50 [32%]) and in 2 cases of apparently idiopathic usual interstitial pneumonia. Apart from the possible diagnostic information of this finding, in patients with SSc, the globules were significantly related to BAL neutrophilia or eosinophilia and extensive ILD in high-resolution computed tomography (P < .0001). Differential diagnosis with other types of acellular globular materials observed in BAL samples is also discussed.