Vascular etiologies of unilateral pulmonary fibrosis: Case series and literature overview

Unilateral pulmonary fibrosis (UPF) is an uncommon manifestation of interstitial lung disease that may arise from various causes. Among those, cardiovascular etiology is often overlooked because affected patients do not present history of exposure of any kind, are frequently asymptomatic or present only mild, subtle and nonspecific symptoms. As a result, these cases are usually identified incidentally on imaging performed for unrelated reasons, contributing to under recognition of their true prevalence. We report 3 patients with incidentally detected UPF on high-resolution computed tomography (HRCT), each associated with a distinct vascular abnormality, both congenital and acquired conditions: unilateral absence of the pulmonary artery, chronic pulmonary thromboembolism, and pulmonary artery branch hypoplasia. Our aim with this case series is to highlights the diverse radiologic patterns of vascular UPF, underscoring the importance of considering vascular causes in the differential diagnosis of unilateral fibrotic lung disease.