再発性結腸癌に合併したIgG4関連腎臓病

IgG4-related kidney disease showing multiple diffuse bilateral kidney lesions proceeded by recurrent transverse colon cancer：A case report

　症例は65歳男性。再発性結腸癌の経過観察中にCTで両側腎に多発性のくさび型造影不良域を認めたために当科紹介。自己免疫疾患の腎病変の可能性を考慮し，血清IgGとIgG4の高値を認めたためにCTガイド下生検を施行した。免疫染色でIgGおよびIgG4陽性の形質細胞を認め，IgG4関連腎臓病と診断し，プレドニゾロンによる内服治療を開始した。血清IgG4は基準値まで下降し，CTで両側腎病変は縮小傾向にあり，画像的にも治療効果が認められた。

A 65-year-old male with recurrent transverse colon cancer was referred to our department for further examination of multiple wedged-shape diffuse bilateral kidney lesions revealed by CT scan. As serum IgG and IgG4 were elevated, we regarded these lesions as autoimmune disease. Therefore he underwent percutaneous CT guided renal biopsy. Immuno-histochemical study showed IgG and IgG4 positive plasma cell-dominant inflammatory cell infiltrated densely in the renal interstitium. Based on these findings we diagnosed these lesions as IgG4-rerated kidney disease. Corticosteroid therapy normalized sereum IgG, IgG4 level and reduced bilateral kidney lesions on CT scan.