Histologic growth patterns of metastatic carcinomas of the liver.

One hundred autopsied livers containing metastatic cancers were studied pathologically. Macroscopically, the cancers were of the multinodular type in 65.0% of cases, massive type in 17.0% and portal tract type in 8.0%. Among liver metastases from colon and lung cancers, most cases showed predominantly intraparenchymal growth (92.3% and 87.5%, respectively). In contrast, among liver metastases from gallbladder/bile duct cancer, intraparenchymal growth was less frequent (35.7%). With regard to the histologic growth pattern at the boundary of the liver metastases, in micrometastases less than 1 mm in diameter a replacement growth pattern was predominant among metastases from lung, colon and pancreas cancers (69.7%, 79.3% and 66.7%, respectively), whereas a sinusoidal growth pattern was predominant in those from gastric and gallbladder/bile duct cancers (48.5% and 66.7%). Among macrometastases of the liver over 20 mm in diameter, an expansive growth pattern was predominant, irrespective of the cancer primary site. Thus metastatic liver cancers showed changes in growth patterns according to the size of the metastatic tumors.