differentiation between morphologically aggressive and non-aggressive basal cell carcinoma by agnor staining

argyrophilic staining of nucleolar organizer regions (agnor) has been considered to be useful in the diagnosis and prognostic evaluation of different cutaneous tumors. in order to evaluate the role of the agnor technique in discriminating aggressive from non-aggressive basal cell carcinoma (bcc), paraffin-embedded histologic sections from 30 cases of aggressive bcc (bcc2) and 30 cases of non-aggressive bcc (bcc 1) were investigated for nucleolar organizer regions (nor), and these cases were categorized on the basis of histologic criteria. the means of agnor counts were higher in bcc2 than bcc1 without overlapping in the range of nor numbers. in bcc2 the majority of the dots had irregular borders and were of varying sizes, whereas in bcc 1, the dots had regular borders with little variation in size. the means of agnor counts were 4.81 with an sd (standard deviation) of 0.88 for aggressive and 2.39 with an sd of 0.61 for the non-aggressive group. the difference was statistically significant (p value= 0.000). the agnor number, their configuration and size, may provide information to be useful for recognition of aggressive bcc. considering histologic criteria, agnor counting and clinical features, we can predict the behavior of most bcc tumors.