食道胃接合部癌に対するニボルマブ投与後に発症した免疫関連膀胱炎

A case of sterile cystitis occurring after nivolumab administration for esophagogastric junction cancer

　症例は51歳，男性．食道胃接合部癌に対してニボルマブ投与後に排尿時痛，肉眼的血尿を認めた．細菌性膀胱炎を疑い抗菌薬を投与するも症状は改善せず，尿培養，尿細胞診は陰性，膀胱鏡ではびまん性膀胱壁肥厚を認めた．ニボルマブによる免疫関連膀胱炎を疑いプレドニゾロン1mg/kg/日にて投与を開始したところ7日後に症状の改善を認めた．その後の症状再発はなく，原疾患の再発転移は認めなかった．

Abstract

A 51-year-old male patient developed dysuria and macroscopic hematuria three months after initiating nivolumab for esophagogastric junction cancer. His symptoms were unresponsive to antibiotic treatment, and both urine culture and urine cytology were negative. Cystoscopic examination revealed diffuse thickening of the bladder wall. A diagnosis of nivolumab-induced aseptic cystitis was suspected, and prednisolone was administered at a dose of 1 mg/kg/day. Symptomatic improvement was observed seven days after initiating treatment. A follow-up CT scan performed ten months later showed no progression of the primary disease. In the future, further accumulation of cases is expected to establish an optimal management strategy for immune-related cystitis (Rinsho Hinyokika 79 : 1101-1105, 2025).