組織生検で診断に至ったIgG4関連後腹膜線維症の1例

Abstract

An 82 -yearold man presented to our department in December 2020 with a complaint of right lumbar back pain. An abdominal computed tomography showed an irregular mass at the right renal hilum. The abdominal CT, retrograde pyelography, and urine cytology did not reveal a renal or urinary tract malignancy, and retroperitoneal fibrosis was also suspected. An echoguided biopsy was performed to confirm the diagnosis because of high levels of serum IgG and IgG4. The histopathological specimens showed diffuse lymphocyte aggregation and fibrosis. The patient was diagnosed as having IgG4related retroperitoneal fibrosis because the IgG4/IgGpositive cell ratio increased to 40 or more. After treatment with prednisolone 20 mg/day, the right hilar mass shrank and the serum IgG4 level decreased.