title: Hepatocellular carcinoma developed on noncirrhotic livers. Sinusoids in hepatocellular carcinoma.
abstract: In hepatocellular carcinoma, there is modification of cell-to-cell and cell-to-extracellular matrix interactions. Two cases of well-differentiated hepatocellular carcinoma that developed in noncirrhotic livers were explored by light and electron microscopy on perfusion-fixed liver biopsy specimens. In addition, immunocytolocalization of collagen types I, III, and IV, laminin, and fibronectin was assessed. The main features included the following: absence of collagen staining inside the tumor with Sirius red; decrease of collagen types I and III and the increase of collagen type IV, laminin, and fibronectin; widening of Disse's spaces containing numerous, discontinuous, and thick fragments of basement membrane-like material piled up beneath endothelial cells and around perisinusoidal cells; transformation of perisinusoidal cells into cells with the characteristics of fibroblasts and myofibroblasts; decreased numbers of fenestrae for endothelial cells with processes often overlapping and attached with tight junctions; and rarefaction of Kupffer's cells. Expression of cellular and extracellular material abnormalities are related to the tumor differentiation. The study of these abnormalities may have implications in prognosis.
mesh_terms: D002196:Capillaries / Q000378:metabolism / Q000648:ultrastructure; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000209:etiology / Q000648:ultrastructure*; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism / Q000648:ultrastructure; D006651:Histocytochemistry; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000378:metabolism / Q000648:ultrastructure*; D008113:Liver Neoplasms / Q000098:blood supply / Q000209:etiology / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged
chemical_list: D003094:Collagen