Figure 2

Histology of invasion fronts of liver metastases from the clinical specimen and from the murine model. HE staining of the invasion front of five clinical specimens (H1–H5) and murine tumors (M, CT26) growing in the livers of Balb/C mice. The human tumors were moderately to lowly differentiated adenocarcinomas with moderate stroma production and stroma reaction by a mild lymphocytic infiltrate. The tumor part of the invasion front did not differ strikingly from the inner parts. The liver displays an orderly structure with some fibrosis and a mild to moderate lymphocytic infiltrate in the portal tracts, no major pigments and mild to moderate fatty degeneration. The liver part of the invasion front contains mainly hepatocytes, but, in addition, an increased number of inflammatory and fibroblast like cells as well as sporadically ECM-like deposits. The murine tumor is a lowly differentiated to undifferentiated adenocarcinoma with little stroma production and little stromal reaction. As in the clinical samples the tumor does not significantly differ from the tumor part of the invasion front. The livers are of orderly structure with no apparent abnormalities. The liver part of the invasion front does not display gross differences to the liver except that the hepatocytes appear to be slightly flattened. Areas of microdissection are displayed exemplarily (H1).