6th ESACP Congress, Heidelberg, April 7-11, 1999

A160
EPITHELIAL MEMBRANE ANTIGEN QUANTITATIVE IMMUNOCYTOCHEMICAL ANALYSIS IN ORAL LESIONS AND ORAL SQUAMOUS CELL CARCINOMAS
Fernandez Alvarez BE 1, Lopez-Muñiz 1, Anitua MJ 1, Triviño A 1, Garcia-Pola JMJ 2

1 Dept. Morphology and Cellular Biology, 2 Dept. Oral Surgery, School of Dentistry, Faculty of Medicine, University of Oviedo, Spain

A series of 102 normal mucosas, 102 oral non-dysplastic leukoplakias, 88 oral dysplastic lesions and 102 squamous cell carcinomas, were evaluated in paraffin-embedded sections using E29 Epithelial Membrane Antigen, EMA, monoclonal antibody. Quantitative analysis of immunoreactivity (EMA positive surfaces and percentage of immunopositive cells) was assessed. EMA immunostaining had high ability to establish the difference between benign and malignant cells of squamous epithelia. Its distribution was detected with typical patterns for each type of mucosa. In normal, non-dysplastic lesion, dysplasia and carcinoma, the quantitative immunohistoanalysis found 1.8%±1.2; 4.6%±2.2; 21.6%±15.2 and 35.5%±22.7 of EMA-positive surfaces, respectively; and the cases of more than 20% EMA positive cells were 0%; 0%; 37.5% and 98%, respectively. EMA affinity, both in premaligant lesions and in squamous cell carcinomas, was correlated with significant changes of the proliferating cellular nuclear parameters. The percentage of EMA positive cells showed a significant correlation with mitotic index, diploid index (p< 0.01), hyperploid degree (p< 0.01) and AgNORs size (p< 0.01) in carcinomas. The EMA expression within squamous epithelial cells has to be investigated by quantitative immunohistochemical methods and used as a diagnostic indicator.