Nivolumab is an immune checkpoint inhibitor (ICI), which is used for treatment of advanced malignancies. Diarrhea is a typical adverse effect of ICIs. Several endoscopic features of ICI-related colitis have been reported. Herein, we reported a case of ICI-related colitis, with successful follow-up using ultrasonography (US). A 54-year-old woman, diagnosed with renal cell carcinoma, underwent radical nephrectomy. Multiple liver and bone metastases appeared 6 months after surgery. She was prescribed sunitinib, which was discontinued, because of severe diarrhea. She was prescribed nivolumab after 1 week. However, she was hospitalized 9 days later, due to fever and diarrhea. US showed diffuse wall thickening from the cecum to the rectum. The wall layer structures were preserved, and thickening was observed mainly in the submucosa, but not in the mucosa, without a decrease in the echo level. Subsequently, sigmoidoscopy was performed. Severe edema was observed in the mucosa, without any erosion and granularity. She was clinically diagnosed with ICI-related colitis, and steroid therapy was administered. One week after steroid therapy, the diarrhea improved, and the earlier findings showed marked improvement on US. After another week of reduced steroid dose, US revealed further improvement, and she was discharged.

中文翻译：

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超声检查成功随访了免疫检查点抑制剂引起的结肠炎

Nivolumab是一种免疫检查点抑制剂（ICI），用于治疗晚期恶性肿瘤。腹泻是ICI的典型不良反应。已经报道了ICI相关性结肠炎的几种内窥镜特征。本文中，我们报道了1例ICI相关性结肠炎，并通过超声检查（US）成功随访。一名54岁的女性，被诊断患有肾细胞癌，接受了根治性肾切除术。术后6个月出现多发肝和骨转移。为她开了舒尼替尼的处方，由于严重腹泻而停药。1周后给她开了nivolumab的处方。但是，由于发烧和腹泻，她在9天后住院。US显示从盲肠到直肠的弥漫性壁增厚。保留了壁层结构，并且主要在粘膜下层观察到增厚，但不在粘膜中，而回声水平却没有降低。随后，进行乙状结肠镜检查。在粘膜中观察到严重水肿，没有任何侵蚀和颗粒状。她在临床上被诊断出患有ICI相关性结肠炎，并接受了类固醇治疗。类固醇治疗后一周，腹泻得到改善，早期发现表明超声治疗明显改善。在降低类固醇剂量的另一周后，US显示出进一步的改善，她已出院。