Improvement of Lymphedema in IgG4-Related Disease with Oral Glucocorticoid Therapy

An 81-year-old Japanese man with IgG4-related disease (IgG4-RD) presented with marked edema in the right lower leg. He was diagnosed with IgG4-RD with retroperitoneal fibrosis, hilar and mediastinal lymphadenopathy, elevated serum IgG4 levels, and IgG4-positive plasma cell infiltration in a mediastinal lymph node. Lymphatic scintigraphy revealed an obstruction corresponding to edema due to retroperitoneal fibrosis. Glucocorticoid therapy resulted in rapid improvement. Lymphedema due to IgG4-RD with retroperitoneal fibrosis is rare and no standard treatment exists. This case underscores the importance of considering IgG4-RD which is a potentially reversible cause of lymphedema.