A Case of IgG4-Related Pancreas and Kidney Disease Mimicking a Renal Pelvic Malignancy

신우 종괴 형성과 췌장 침범을 동반한 IgG4 연관 경화성 질환 1예

IgG4-related sclerosing disease is a disease entity that has recently attracted attention, manifesting as a multiorgan disease characterized by high serum IgG4 levels, extensive IgG4-positive plasma cells and lymphocyte infiltration of the affected organs, with the pancreas (autoimmune pancreatitis) and kidney as representative targets. In cases of renal involvement, parenchymal lesions are predominant, such as renal cortical lesions or diffuse renal enlargement. However, mass-like lesions involving the renal pelvis are very rare, and mass forming or pelvic involvement types should be distinguished from lymphomas, metastatic cancers and other genitourinary malignancies to avoid unnecessary surgery. Herein, we report a case of IgG4-related sclerosing disease involving the kidney as an unusual involvement pattern presenting as a mass-like lesion with pelvic and perirenal involvement.