Abstract

Immunoglobulin G4 - related disease (IgG4-RD) is a multisystemic fibro inflammatory disorder that can involve multiple organs and organ systems of the body. While autoimmune pancreatitis and retroperitoneal fibrosis are the most described forms of this entity, a few patients may present with thoracic involvement, either in isolation or more commonly, in association with abdominal and other systemic manifestations. Thoracic presentation of the disease can be in the form of lung parenchymal, interstitial, mediastinal vasculature and pleural involvement. In the mediastinal vasculature, thoracic aorta is the most commonly involved vessel; involvement of the pulmonary artery is less frequently described in literature. We present the imaging findings of an unusual case of IgG4-RD with isolated thoracic involvement in a middle-aged male patient who presented with shortness of breath.Contrast enhanced CT of the chest revealed a poorly marginated mediastinal mass causing encasement and narrowing of the superior vena cava, encasement and cut-off of the right pulmonary artery, with extension of the soft tissue along the right peribronchial interstitium.A solid nodule and mild interstitial changes were also seen in the right lung as part of the disease spectrum.