Fibronectin in differential diagnosis of primary hepatomas and carcinoma metastases in the liver.

Human liver specimens with primary hepatocellular and cholangiocellular carcinoma and liver metastases of cancers from different organs were studied for the distribution of fibronectin (Fn) by immunoperoxidase staining. With the exception of an undifferentiated type, all six well and moderately differentiated primary hepatocellular carcinomas contained Fn in the intercellular spaces and on the surface of certain cells of the tumour parenchyma, while in the case of three cholangiocarcinomas Fn could only be detected in the loose reactive connective tissue stroma. No Fn was observed around individual tumour cells in any of eleven carcinoma metastases in the liver. These findings indicate that hepatocellular but not cholangiocellular carcinomas synthesize Fn, while carcinoma metastases from other organs do not contain Fn in their parenchyma only in the reactive stroma. In this way the presence of Fn in the pericellular matrix of the tumour parenchyma may help to distinguish primary hepatomas from metastases. Metastases with strong fibroplastic character and pericellular fibrosis may, however, imitate Fn production.