SIGNIFICANCE OF ENDOTHELIUM IN THE FINE-NEEDLE ASPIRATION BIOPSY DIAGNOSIS OF HEPATOCELLULAR-CARCINOMA

We reviewed fine-needle aspiration biopsies (FNAB) of hepatocellular c arcinoma (HCC) (n = 35), benign hepatic processes (n = 35), cholangioc arcinoma (CC) (n = 6), and metastatic tumors (n = 100) to evaluate the significance of endothelium present either peripherally-wrapping arou nd groups of cells, (peripheral endothelium (PE)), or transgressing sh eets of cells (transgressing endothelium (TE)), in distinguishing thes e lesions. These patterns were assessed as absent, focal, or prominent . Thirty-three of 35 (94%) HCCs contained either focal or prominent PE or TE, compared to only 3 of 35 (9%) benign hepatocytic lesions. Only one benign lesion contained a prominent endothelial component (TE onl y). Two cases of HCC failed to contain endothelium, one fibrolamellar variant and one well-differentiated HCC. These differences were statis tically significant (P < 10(-5), sensitivity 94%, specificity 91%, and positive predictive value [PPV] 92%). Neither pattern of endothelium was present in any CC or metastatic tumor. These differences were also statistically significant (P < 10(-5), sensitivity 94%, and specifici ty and PVP 100%). We conclude that the presence of endothelium, at lea st focally in either one or both distinctive patterns, is highly sensi tive and specific for HCC and aides in distinguishing it from benign h epatocytic lesions, CC, and metastases. Diagn Cytopathol 1995;12:208-2 14. (C) 1995 Wiley-Liss, Inc.