COMPARING FLOW CYTOMETRIC ANALYSIS AND NUCLEOLAR ORGANIZER REGION ENUMERATION IN ARCHIVAL ORAL PREMALIGNANT LESIONS

Flow cytometric analysis (FCA) and silver colloidal nucleolar organize r region-associated protein staining (AgNOR) have been used individual ly in assessing the histopathologic nature of various human tumors. Ho wever, few researchers have investigated the relationship between the two techniques in a single series. In a retrospective study, we examin ed 36 premalignant lesions of the oral cavity by FCA and AgNOR on form alin-fixed, paraffin-embedded tissue submitted to the University of Te nnessee, Memphis, oral pathology laboratory. Three categories of epith elial dysplasia were represented (9 mild, 9 moderate, 6 severe), as we ll as four epithelial hyperplasias without dysplasia, three squamous c ell carcinomas, and five fibrous nodules as controls. Parameters recor ded for each case included age, race, gender, site, light microscopic diagnosis (LMD), DNA index (DI), total proliferative index (TPI), S-ph ase (S), range of nucleolar organizer regions (RNOR), and mean number of nucleolar organizer regions (MNOR). The average maximum nucleolar o rganizer region count (AMXNOR) for each LMD category was also calculat ed. The objective of the study was to determine if FCA or AgNOR aided in the subjective LMD of oral premalignant lesions and if the paramete rs recorded for the specimens exhibited any positive correlation. The FCA results indicated an abnormal DI in 6 of the 24 dysplastic lesions . A positive partial correlation was seen between DI and MNOR (r=0.434 ; P < 0.012) and TPI and S (r=0.774; P< 0.0001), holding gender and ra ce constant. Additionally, the AMXNOR exhibited a slight tendency to i ncrease for each increasing grade of dysplasia but this could not be c onfirmed statistically. The results indicate that there is a positive correlation between FCA and AgNOR but that neither FCA nor AgNOR were a diagnostic aid in grading oral mucosal dysplasia.