AgNOR count as objective marker for dysplastic features in oral leukoplakia

Background: Dysplasia is an important feature of leukoplakia. Because agreement among oral pathologists is poor regarding lesional diagnosis, silver stainable nucleolar organizer regions (AgNORs) as replicatory markers may have a place in objectively characterizing dysplasia in tissue specimens. Methods: We studied 41 normal oral epithelia, 51 oral leukoplakia (26 dysplastic, 25 non‐dysplastic), and 51 cases of squamous cell carcinoma specimens for their mean AgNOR counts. Results: Mean AgNOR counts increased gradually from normal epithelium to non‐dysplastic to dysplastic leukoplakia to squamous cell carcinoma. Using ROC analysis, we determined a mean AgNOR count cut‐point (2.37) that can be used to distinguish between dysplastic and non‐dysplastic leukoplakia. The test had a sensitivity of 75% and specificity of 83% with area under the curve being 88%. Conclusions: Mean AgNOR count could be a valuable criterion for defining objective parameters for diagnosis/determination of dysplasia distinguishing between dysplastic and non‐dysplastic leukoplakia.