A case of IgG4-related renal pseudotumor in a child with history of Wilms tumor

摘要

IgG4-related disease (IgG4-RD) is a novel immune-mediated systemic disease characterized by lymphoplasmacytic infiltration and fibrosis of tissues.1 While the pathophysiology has yet to be elucidated,malignancy has been shown to be associated with future developmentof IgG4-RD.2 IgG4 pseudotumors fall within the scope of IgG4-RD, mostcommonly presenting as orbital, pancreatic, pulmonary, hepatic, orthyroid masses, although involvement of other organs has been described.3 Originally described in 2003, there is a paucity of literatureregarding IgG4-RD in the pediatric population. There have been 3 reported cases of renal IgG4-RD in children, with all cases having multiorgan involvement.3 Herein, we describe the first case of an isolatedrenal IgG4 pseudotumor in an 11-year-old boy with a history of previously treated Wilms tumor (WT).