[Clinicopathological significance of intrahepatic micrometastases in hepatic metastatic carcinomas].

The micrometastases confirmed only by microscopic examination were investigated in resected liver specimen of hepatic metastatic carcinomas. Twenty three hepatic metastases from gastrointestinal carcinomas were subjected. The micrometastases defined as histologically discontinuous from macroscopic metastatic nodules and less than 1mm in diameter, were found in 8 cases (34.8%). These were 0.2 to 1.0mm (0.52 +/- 0.35, mean +/- SD) in diameter, 1 to 19 (4.1 +/- 6.0) in number and were 2.0 to 29.0 mm distant from the macroscopic metastatic nodules. Histological localization of these metastases were in portal vein in most of cases and rarely in sinusoidal space and hepatic vein. These results suggest that the surgical margin in hepatectomy for hepatic metastases is required more than 3 cm from the tumor and therefore wedge resection is not suitable for the choice of the operative procedure for hepatic metastases because of unsatisfactory surgical margin.