Evaluation of the CD34 and CD10 immunostains using a two-color staining protocol in liver fine-needle aspiration biopsies.

Fine-needle aspiration (FNA) biopsies of liver masses may need immunohistochemistry to resolve difficult cases. We examined liver FNAs with CD10 and CD34 using a two-color staining protocol. Fifty-one cases of hepatocellular carcinoma (HCC) and 23 cases of liver metastases were stained first with CD10 using diaminobenzidine as a chromogen and then with CD34 using Fast Red. All cases were reviewed in a blinded fashion by two of the authors (R.I.Z. and Z.B.). Diagnoses were unblinded and staining patterns evaluated. Forty-eight of 51 cases of HCC stained for CD34 in a peripheral pattern and no cases of metastases stained for CD34 Seven of 23 cases of metastatic disease stained for CD10 in a diffuse cytoplasmic distribution and 29 of 51 HCCs stained in a canalicular pattern. Overall, the sensitivity of the CD10/CD34 combination was 98% and the specificity was 100% for HCC when appropriate staining patterns were observed. Two-color immunostaining with CD10 and CD34 may prove useful in distinguishing HCC from metastases.