Relapsing IgG4-related orbital inflammatory pseudotumor after achieving success with rituximab

IgG4-related disease (IgG4-RD) is a disease of fibroinflammatory with infiltration of IgG4-positive plasma cells. The lesions show focal or diffuse nodular formations in one or multiple organs; due to the infiltration of lymphocytes and plasma cells with fibrosis. The IgG4-DR is recognized as an important cause of idiopathic inflammatory disease that must be differentiated with other pathologies. The measurement of normal IgG4 levels is not enough to exclude IgG4-RD. The treatment covers the symptomatic aspect and use of systemic corticosteroids (CS), and immunomodulatory and biological therapy. The relapsing is might be misdiagnosis. We propose to consider the imaging follow-up for the therapeutic management