Argirophilic nucleolar organizers regions in benign fibro-osseous lesions

The purpose of this study was to compare argirophilic nucleolar organizer r egion (AgNOR) numbers in distinct benign fibro-osseous jaw lesions to verif y a possible correlation between the known biological behaviour of these en tities and the metabolic activity of tumoural cells. 31 neutral-buffered, f ormalin-fixed tissue blocks representing 13 cases of fibrous-dysplasia, 14 cases of cemento-ossifying fibroma and four cases of cemento-osseous dyspla sia were selected. Two serial 4 mu m sections were made from each block. On e was stained with haematoxylin and eosin. The other was stained according to the AgNOR method. The differences in AgNOR counts amount fibrous-dysplas ias (1.55 +/- 0.21), cemento-osseous dysplasias (1.62 +/- 0.20) and cemento -ossifying fibroma (1.54 +/- 0.19) were not statistically significant (P > 0.05). Thus differences in the clinical behaviour, reported in the literatu re, among these benign fibro-osseous lesions, are not related to their cell ular ratio proliferation and then are not reflected by AgNOR counts. Med Sc i Res 27:191-192 (C) 1999 Lippincott Williams & Wilkins.