復發性多灶性腎細胞癌異時性膀胱轉移-病例報告

李宗翰¹、彭昱璟³、黃逸修^1,2

¹臺北榮民總醫院泌尿部；2國立陽明交通大學醫學院泌尿學科及書田泌尿科學研究中心；3臺北榮民總醫院病理檢驗部

Metachronous Metastatic Renal Cell Carcinoma
to the Urinary Bladder - A case report
Tsung-Han Li¹, Yu-Ching Peng³, Eric Yi-Hsiu Huang^1,2

¹Department of Urology, Taipei Veterans General Hospital, Taipei, Taiwan

²Department of Urology, College of Medicine and Shu-Tien Urological Science

Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan

³Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan

Introduction: Urinary bladder metastasis from renal cell carcinoma (RCC) is a rare clinical entity. Its metachronous occurrence and underlying pathobiological mechanisms present diagnostic and therapeutic challenges in the management of RCC. Here, we report a case of recurrent multifocal RCC presenting as gross hematuria, with subsequent confirmation of bladder metastasis.
Case Presentation: A 64-year-old man with a history of left clear cell renal cell carcinoma initially underwent open partial nephrectomy in December 2010. The initial staging of the tumor was pT3aN0M0, Fuhrman grade 2. Despite subsequent systemic therapy, he later developed recurrent disease with metastases to the pancreas and brain, for which he underwent left radical nephrectomy, distal pancreatectomy, and craniotomy. Thereafter, he received multiple lines of systemic treatment, including sunitinib, nivolumab, pembrolizumab, axitinib, lenvatinib, and everolimus, as well as focal cryoablation for right renal and adrenal metastases. In January 2024, a new right parietal brain metastasis was identified and treated with Gamma Knife radiosurgery.

In May 2025, he presented with painless gross hematuria for one month. Further evaluation was arranged on May 13, 2025. Urine cytology was negative for malignant cells. KUB revealed no radiopaque urinary stones, whereas lower abdominal ultrasonography demonstrated a 2.2-cm nodule over the right lateral wall of the urinary bladder. Subsequent cystoscopy disclosed a non-papillary, polypoid, erythematous tumor over the right lateral bladder wall. After detailed discussion and shared decision-making, he underwent transurethral resection of bladder tumor (TURBT) on June 20, 2025. Intraoperatively, a polypoid tumor located at the 9 o’clock position of the bladder neck was identified and completely resected. He was discharged on postoperative day 3 after removal of the Foley catheter. Pathological examination revealed metastatic clear cell renal cell carcinoma. Immunohistochemical staining showed the tumor cells were positive for CAIX and CK, and negative for GATA3. BAP1 expression was preserved. Muscularis propria was present and free of tumor involvement. He subsequently underwent repeat TURBT on October 15, 2025, and pathology revealed benign tissue only. Follow-up MRI on November 4, 2025, demonstrated stable disease.

Conclusions: Urinary bladder metastasis from RCC is an uncommon but important diagnostic consideration in patients with a history of RCC who present with gross hematuria. This case highlights the unpredictable and metachronous metastatic behavior of RCC, even after prolonged multimodal treatment and long-term follow-up. Timely cystoscopic evaluation, transurethral resection, and histopathological confirmation with immunohistochemical studies are essential for accurate diagnosis. Clinicians should remain alert to atypical metastatic sites during surveillance, as early recognition may facilitate appropriate local management and ongoing systemic treatment planning.