MORPHOL.–EMBRYOL., 1999–2004, XLV, p. 97–118 THE IMMUNOHISTOCHEMICAL PROFILE OF LUMINAL EPITHELIAL NEOPLASTIC COMPONENT FROM PLEOMORPHIC ADENOMAS OF SALIVARY GLANDS CL. MĂRGĂRITESCU*, MARIA FLORESCU**, M. RAICA***, CRISTIANA SIMIONESCU*, L. MOGOANTĂ****, E. PREDA***** *Department of Pathology, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova; **Department of Pathology, Faculty of Medicine, University of Medicine and Pharmacy of Craiova; ***Department of Histology, Faculty of Medicine, University of Medicine and Pharmacy, “Victor Babeş” Timişoara; ****Department of Histology, Faculty of Medicine, University of Medicine and Pharmacy of Craiova; *****Military Clinical Emergency Hospital “Ştefan Odobleja”, Craiova Summary. The immunohistochemistry study made on 30 cases of salivary glands pleomorphic adenomas aims to establish the antigen profile of luminal epithelial neoplastic component proliferates into these tumors. We ascertain that luminal epithelial neoplastic cell were almost exclusively positive to antibody peculiar to epithelial differentiation (AE1/AE3, MNF 116, CK 8, CK 19, CK20, EMA) and occasional to S-100 protein and negative to vimentin, α-smooth muscle actin, calponin, Glial Fibrillary Acidic Protein (GFAP). This kind of immunoreactivity was similar to ductal cells from striated channels of salivary glands, suggesting the origin of such pleomorphic adenomas from this place. Key words: immunochemistry, epithelial component, pleomorphic adenoma, salivary gland. INTRODUCTION The salivary gland pleomorphic adenoma is a benign epithelial neoplasm, histologically characterized by a great diversity of morphological aspects. Its structural pleomorphism is given both by the epithelial component, as a result of the cytological differentiations and the growing patterns, and by the stromal component because of its rich morphological and quantitative diversity [1, 2]. Two distinctive cellular populations have represented the basic cellular components of this kind of tumor: a luminal one (represented especially by the ductal luminal cell) and an abluminal one (represented by the myoepithelial cell and the myoepithelial- like cells derived from it). The luminal cell from normal salivary glands has the following antigen profile: – the acinar one is: intense positive to cytokeratins with low molecular weight, weak positive for cytokeratins with high molecular weight, intense positive to Amylase, weak positive for Lactoferrin, Lysosym, Carcinoembryonic Antigen