Pleomorphic Adenoma: Immunohistochemistry
This high magnification image of a pleomorphic adenoma (PA) shows predominantly solid growth pattern of the epithelial cells surrounded by myxochondroid matrix. Immunohistochemistry: Immunohistochemically, PA shows variable staining pattern from case to case and also within the same case. Epithelial cells in PA are cytokeratin, CEA and EMA positive; myoepithelial cells are cytokeratin, P63, P40, calponin, S100, GFAP, actin and vimentin positive but are CEA and EMA negative. PLAG1 (pleomorphic adenoma gene 1) and SOX10 show nuclear positivity in both epithelial and myoepithelial cells. Ki 67 index is usually less than 5%. Immunoreactivity for PSA and PSAP has been noted in about 50% of PA cases.