DIAGNOSTIC VALUE OF SILVER-STAINED NUCLEOLAR ORGANIZER REGIONS IN OSTEOSARCOMA, FIBROUS DYSPLASIA AND OSSIFYING FIBROMA OF THE JAWS

It is sometimes difficult to recognize a jaw lesion as osteosarcoma, ossifying fibroma orfibrous dysplasia in routine hematoxylin and eosin staining and a more accurate technique is needed todifferentiate these lesions. many studies have shown the potential usefulness of silver-stained nucleolarorganizer region (agnor) parameters for the diagnosis of various neoplasms. this study was carriedout on 42 archival biopsy specimens of jaw lesions including 14 fibrous dysplasias, 14 ossifyingfibromas and 14 osteosarcomas (10 well differentiated and 4 poorly differentiated). number ofagnors was evaluated on formalin-fixed, paraffin embedded sections. the mean agnor countsshowed significant differences between these lesions. the mean counts of agnors were < 1 forfibrous dysplasia, 1 to 2.5 for ossifying fibroma and well differentiated osteosarcoma, and > 6 forpoorly differentiated osteosarcoma. by considering a cutoff point of 1.81-2.5 for well differentiatedosteosarcoma and 1-1.8 for ossifying fibroma, well differentiated osteosarcoma can be differentiatedfrom ossifying fibroma with a sensitivity of 90% and a specificity of 64.3%. the area under the roccurve was 0.84. the results in this study indicate that agnor staining is a useful technique fordifferential diagnosis of osteosarcoma, ossifying fibroma and fibrous dysplasia of jaws when it isdifficult to recognize these lesions in routine hematoxylin and eosin staining.