本文报道一例异体肾移植术后9年确诊原发性肌层浸润性膀胱尿路上皮癌的男性患者。患者因"无痛性全程肉眼血尿1周"就诊，计算机断层扫描（CT）及磁共振成像（MR）显示膀胱底及右侧壁占位性病变。经尿道膀胱肿瘤电切术（TURBT）术后病理提示高级别浸润性尿路上皮癌。鉴于患者长期接受免疫抑制治疗，合并多种基础疾病（特别是严重心功能不全），无法耐受根治性膀胱切除术及标准化疗，遂采用抗体偶联药物（ADC）维迪西妥单抗进行单药靶向治疗。经广东省医学会泌尿外科疑难病例多学科会诊，专家认为患者无手术适应证，且不适宜联用免疫检查点抑制剂，建议将免疫抑制方案调整为兼具抗肿瘤潜能的西罗莫司，并完善基因检测以指导后续靶向治疗。经与患者及家属充分沟通后，继续完成既定疗程的维迪西妥单抗治疗。完成第11周期治疗后，二次膀胱镜检及病理活检提示原肿瘤区域未见癌组织残留，达到病理学完全缓解。治疗期间患者除脱发外，未出现明显不良反应。该病例表明，对于肾移植术后一般状况差、无法耐受标准治疗的肌层浸润性膀胱癌患者，维迪西妥单抗单药治疗是一种颇具前景的有效选择。

This article reports a case of primary muscle-invasive urothelial carcinoma of the bladder diagnosed in a male patient 9 years after allogeneic kidney transplantation. The patient presented with a one-week history of painless gross hematuria. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a space-occupying lesion at the bladder base and right wall. Pathological examination following transurethral resection of the bladder tumor (TURBT) indicated high-grade invasive urothelial carcinoma. Given the patient's long-term immunosuppressive therapy, multiple comorbidities (particularly severe cardiac dysfunction), and inability to tolerate radical cystectomy or standard chemotherapy, monotherapy with the antibody-drug conjugate (ADC) disitamab vedotin (RC48) was initiated. A multidisciplinary consultation organized by the Guangdong Urological Association concluded that the patient was not a surgical candidate and was unsuitable for combined immunotherapy. It was recommended to switch the immunosuppressive regimen to sirolimus, which has potential antitumor effects, and to perform genetic testing to guide further targeted therapy. After communication with the patient and family, treatment with disitamab vedotin was continued. After the 11th cycle, a second cystoscopy with pathological biopsy of the original tumor site and margins showed no residual carcinoma, indicating a pathological complete response. The treatment was well-tolerated with alopecia as the only notable adverse event. This case suggests that disitamab vedotin monotherapy is a promising and effective option for renal transplant recipients with muscle-invasive bladder cancer who are ineligible for standard treatments due to poor general condition.