Renal Metastasis of Adenocarcinoma of the Colon.

Introduction: Metastasis is a critical factor in colorectal cancer (CRC) outcomes, with 22% of patients presenting with metastasis at diagnosis and an eventual 70% experiencing it. This report highlights a rare case of ascending colon adenocarcinoma with metastasis to the kidney, underscoring the diverse and complex nature of CRC progression. Case Presentation: A 60-year-old man presented with abdominal discomfort, constipation, and rectal bleeding after colonoscopy revealed a colon mass, leading to a diagnosis of adenocarcinoma after colonoscopic biopsy. Initially without distant metastasis, he underwent four cycles of chemotherapy, but follow-up imaging 6 months later showed liver and renal metastases, prompting a colectomy and nephrectomy. Pathological examination confirmed moderately differentiated adenocarcinoma in both the colon and kidney, with staging indicating advanced disease, and the patient succumbed to his illness shortly after surgery. Clinical Discussion: Metastatic carcinomas to the kidney are uncommon, with CRC metastasis being particularly rare, as evidenced by a limited number of cases in the literature. Typically originating from primary tumors in the lung, liver, and gastrointestinal tract, renal metastases often present as well-defined lesions, complicating the differentiation from primary renal cancers. Our case highlights a solitary, well-circumscribed renal metastasis from CRC, emphasizing the diagnostic challenges and the need for careful evaluation in patients with known malignancies. Conclusion: Metastatic carcinoma of the colorectal tract is very rarely reported to the kidney, it does so at a higher stage of the disease with systemic disease and has a poor outcome for the patient.