S4654 Colonic Metastasis of Renal Cell Carcinoma: A Rare Cause of Lower GI Bleed

Introduction: Renal cell carcinoma (RCC) is the most common urogenital malignancy and carries the highest mortality with a rate of 30-40%. Around 400,000 cases of RCC are diagnosed per year and an estimated 20-33% present with metastases at diagnosis. Treatment for non-metastatic or localized disease is surgical resection; however, approximately 20%-50% will develop metastases despite resection. Metastasis typically involves the lungs, lymph nodes, bones, and liver. Colonic metastases is exceedingly rare. In this case report, we present a case of colonic metastasis from RCC. Case Description/Methods: An 80-year-old man with a history of left-sided RCC with known pulmonary and osseous metastasis presented with rectal bleeding, 40 lb unintentional weight loss over several months, and constipation. Hemoglobin on admission was 6.0 g/dL. Computed tomography imaging revealed a known solid mass of the left kidney and new wall thickening at the splenic flexure, raising concern for colonic malignancy. Gastroenterology (GI) was consulted, and colonoscopy revealed a tortuous, dilated colon and 2-3 cm ulcerated colonic nodule near the splenic flexure. Biopsies showed ulceration but no malignancy. The patient was discharged but returned 1 week later with recurrent rectal bleeding and hemoglobin of 5.5 g/dL. Flexible sigmoidoscopy revealed a friable, ulcerated colonic nodule with active bleeding. Hemostasis was achieved using epinephrine injection and 2 hemoclips. The lesion was resected via hot snare polypectomy. Pathology confirmed metastatic RCC. The patient declined surgical intervention after goals-of-care discussions and transitioned to hospice, passing away shortly thereafter. Discussion: Our case of colonic metastasis presents similarly to the majority of cases in the literature: a patient with known RCC presents with new onset rectal bleeding. While routine surveillance focuses on lungs, liver, and bone, colonic involvement should be considered in symptomatic patients. This case highlights the need for a high index of suspicion for GI metastasis in any RCC patient presenting with rectal bleeding.