Diagnosing liver tumors can be difficult in the setting of a poorly differentiated tumor or tumors with no known prior malignancy. Frequently, alpha-fetoprotein, carcinoembryonic antigen, factor VIII, and mucicarmine have been employed to distinguish hepatocellular carcinoma (HCC) from adenocarcinoma. However, these stains have their limitations. CA 15-3 and Glut-1 are expressed in a variety of carcinomas. To the authors' knowledge, their expression in HCC has not been studied extensively. The authors examined the clinical utility of CA 15-3 and Glut-1 in the setting of fine-needle aspiration biopsy samples from the liver.
Thirty-five cases of HCC and 59 cases of tumors metastatic to the liver were studied. These cases previously were studied with the hepatocyte paraffin-1 antibody. Each case was stained with CA 15-3 and Glut-1 using the avidin-biotin complex method. Each case was evaluated in a blinded fashion for membranous staining that was stronger than cytoplasmic or background staining. The diagnoses were unblinded and staining patterns were compared.
CA 15-3 stained 43 of 59 metastatic carcinoma samples and 3 of 35 HCC samples. Glut-1 stained 34 of 59 metastases and 2 of 35 HCCs. Together, the 2 immunostains stained 51 of 59 metastases and 5 of 35 HCCs. Diagnostic accuracy was improved by adding hepatocyte paraffin-1 to the staining panel.
CA 15-3 and Glut-1, especially in conjunction with hepatocyte paraffin-1, appear to be helpful in discriminating HCC from other carcinomas.