Abstract
Recently, case reports of double primary cancer have been increasing, but the case of double malignancy of the large intestine and kidney is rare. Of 2353 patients with colorectal cancer from 1980 to 1996, six patients had also malignant tumor of the kidney detected before or after the operation for colorectal cancer. Since all of these cases were diagnosed after 1987, an increasing in the incidence appears to be due to routine use of ultrasonography and CT-scan for the staging of the colorectal cancer. The therapeutic result is satisfactory if these double primary malignant tumors are treated in an early stage. We must be careful not to overlook the presence of hematuria in urinalysis as well as abnormal renal image in ultrasonography and CT-scan in the preoperative examination of the colorectal cancer.
