IgG4-related disease causing dacryoadenitis, bronchial stenosis and lobar collapse

Immunoglobulin G4-related disease (IgG4-RD) is a rare systemic fibroinflammatory disease that can affect almost any organ in the body. The most common sites of IgG4-RD include the salivary glands, orbits and lacrimal glands, pancreas, biliary tree, retroperitoneum and thyroid. Immunoglobulin G4-related lung disease (IgG4-RLD) can occur in isolation or as a component of multisystem disease. Its manifestations are heterogeneous and include lung cavitation, interstitial changes, pleural effusions and lung lesions. We describe a patient with Ig4-RLD manifesting as bronchial stenosis and left upper lobe collapse.