Lamellar fibrosis in the fibrolamellar variant of hepatocellular carcinoma: a role for transforming growth factor beta.
Transforming growth factor-beta (TGF-beta) is a pluripotent regulatory molecule, found in at least five different isoforms. It is produced in many different organs. In the liver, TGF-beta is expressed in non-parenchymal cells, but not in hepatocytes. This growth factor is known to induce fibrosis in the course of a variety of pathologic processes. Recently, TGF-beta has also been identified in hepatocellular carcinoma (HCC) cells, and the suggestion has been made that this growth factor may play a role in hepatocarcinogenesis. In this study, we report the findings of immunohistochemical stains for TGF-beta, performed on paraffin sections of 14 human HCCs of the usual type and 11 examples of the fibrolamellar variant (FLC). TGF-beta was detected in tumor cells of 3 HCCs (21%) and 9 FLCs (82%). Compared with the HCCs, the FLCs displayed a more diffuse and intense staining pattern for TGF-beta. Our findings suggest that lamellar fibrosis, which is a histologic hallmark of FLC, may be due to the action of TGF-beta produced by tumor cells.
Orsatti
G
G
Pathology and Laboratory Medicine Service, Veterans Affairs Medical Center, Bronx, NY 10468, USA.
Hytiroglou
P
P
Thung
S N
SN
Ishak
K G
KG
Paronetto
F
F
D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D016212:Transforming Growth Factor beta