Colonic Metastasis of Renal Cell Carcinoma: A Rare Cause of Lower Gastrointestinal Bleeding.

Renal cell carcinoma (RCC) metastasis to the large bowel is exceptionally rare and can present as lower gastrointestinal bleeding. We report the case of an 80-year-old man who presented to our institution with a history of left-sided RCC and known pulmonary and osseous metastases, who presented with recurrent rectal bleeding and profound anemia. Initial colonoscopy demonstrated an ulcerated splenic-flexure nodule, but biopsies were non-diagnostic. One week later, flexible sigmoidoscopy revealed a friable, actively bleeding rectal lesion; endoscopic polypectomy and hemostatic clips were placed. Histopathology confirmed metastatic RCC. Given his advanced disease and functional status, goals-of-care discussions resulted in the initiation of comfort care. This case underscores the importance of maintaining a broad differential for lower GI bleeding in patients with known RCC, including colonic metastasis. Endoscopic evaluation not only facilitates diagnosis but also provides therapeutic hemostasis. A multidisciplinary approach combining gastroenterology and oncology may help ensure accurate diagnosis, effective management, and alignment of care with patient-centered goals of care.