AMACR is not applicable as a diagnostic tool in hepatocellular carcinoma.

Willemoe GL, Vainer B. AMACR is not applicable as a diagnostic tool in hepatocellular carcinoma. APMIS 2010; 118: 85–90. α-methylacyl coenzyme A racemase (AMACR or P504S) is a mitochondrial and peroxisomal protein present in a variety of human cells. Demonstration of increased expression is used diagnostically in prostatic adenocarcinoma. AMACR is also produced by normal hepatocytes and it has been postulated that the demonstration of AMACR expression or its pattern of distribution is useful in the diagnosis of hepatocellular carcinoma (HCC) (Jiang et al., Hum Pathol 2003;34, Guzman et al., Appl Immunohistochem Mol Morphol 2006;14, Li et al., J Exp Clin Cancer Res 2008;27). The aim of the present study was to evaluate whether immunohistochemical staining for AMACR can be used in a routine histopathologic setting. Immunohistochemical staining for AMACR was performed on paraffin-embedded tissue from livers resected for HCC during 1980–2006 at Rigshospitalet, Copenhagen, Denmark (n = 44). Tumor sections as well as surrounding non-neoplastic tissues were studied. In both tumor and non-tumor tissues, intracellular localization and staining pattern were assessed and the staining intensity of AMACR was graded. The fraction of stained tumor cells was not significantly different from that of stained non-tumor cells in the same patients (p = 0.97). A significantly lower staining intensity was observed in clear cell areas (p = 0.005), but the AMACR expression did not correlate with the HCC type and could not distinguish neoplastic from non-neoplastic liver cells. AMACR is not applicable as a tool in the histopathologic diagnosis of HCC.