摘要：The coexistent diagnosis of colorectal cancer and renal cell carcinoma is rare. We reported a 55-year-old woman with history of recurrent UTI, who was admitted to Urology Clinic with left flank pain for the evaluation of renal stone. Ultrasound examination revealed a homogenous mass measuring 4.7cm with a calcified focus in left kidney. Macroscopic evaluation revealed a renal mass in lower pole, 5cm in maximum diameter with variegated cut surface. The pathology report showed clear cell carcinoma of kidney. The patient had a colonoscopy report of many polyps in the entire length of colon with a clinical impression of familial adenomatous polyposis since last year but with no genetic confirmatory tests Since last year, the pathology report showed well differentiated adenocarcinoma of colon invading to submucosa with no vascular and perineural invasion in the distal margin of colon. In family history, her passed brother had colon cancer and her sister was alive with colon cancer that had a colostomy. In summary, the existence of both kidney and colon cancers occurs more in elderly patients. Also, the existence of colon adenocarcinoma with numerous polyps can be a risk factor for the second malignancy that the physicians must pay attention to this point in their follow-up.
