Incidence and detection of occult hepatic metastases in colorectal carcinoma.

Isotope liver scan, ultrasonography, and computed tomography of the liver were performed during the postoperative period in 43 consecutive patients undergoing laparotomy for colorectal carcinoma. Obvious hepatic metastases were detected in six patients at the time of surgery. Eleven patients considered to have a disease-free liver at laparotomy developed hepatic metastases during the two-year follow-up period. These patients were considered to have had occult hepatic metastases at the time of surgery. Postoperative isotope liver scan, ultrasonography, and computed tomography detected the presence of overt metastases in four, five, and six patients respectively. Of the 11 patients with occult metastases, isotope liver scan, ultrasonography, and computed tomography detected one, three, and nine respectively. These observations suggest that 29% of patients undergoing apparently curative resection for colorectal carcinoma possess occult hepatic metastases and that computed tomography is superior to ultrasonography and isotope liver scan in detecting them.