Use of CD34 and factor VIII to diagnose hepatocellular carcinoma on fine needle aspirates

OBJECTIVE: The immunohistochemical staining patterns characteristic of hepatocellular carcinoma (HCC) using CD34 and factor VIII antibodies were compared with those of other hepatic lesions to determine if these stainings can be used as a diagnostic criterion. STUDY DESIGN: We reviewed 44 fine needle aspirates from the liver to evaluate the immunoperoxidase staining patterns on cell block preparations using CD34 and factor VIII and to determine whether this could distinguish HCC from the other lesions. These included HCC (14 cases), metastatic tumor (14 cases) and nonneoplastic liver lesions (16 cases). RESULTS: This retrospective study showed that in the nine documented cases of HCC, staining for CD34 and/or factor VIII was positive. The pattern of staining was either peripheral, around small clusters of tumor cells, or linear, diffuse and sinusoidal. In all the documented cases (27) of metastatic carcinoma and nonneoplastic lesions staining for CD34 and factor VIII was negative. In addition, there were eight problematic cases. In 7 cases the cytologic diagnosis on Papanicolaoustained smears was inconclusive about HCC or metastatic carcinoma. CD34 and factor VIII confirmed the final diagnosis on the cell blocks. Based on this staining, 4 were HCC, 2 were metastatic carcinoma and 1 was equivocal, most probably HCC. In one case the differential diagnosis between well-differentiated HCC and a nonneoplastic liver lesion could not be made on cytologic smears, and here, also, CD34 and factor VIII aided in the correct diagnosis of a nonneoplastic liver lesion. CONCLUSION: We suggest immunoperoxidase staining with CD34 and factor VIII be performed on the cell block sections from FNAs in any problematic hepatic case.