NUCLEOLAR ORGANIZER REGIONS IN LINING EPITHELIUM ADJACENT TO SQUAMOUS-CELL CARCINOMA OF HUMAN ORAL-MUCOSA

Background. The value of silver staining of nucleolar organizer region s (AgNOR) counts as a diagnostic aid has been reported for several neo plastic entities. Previous studies have proved the value of the morpho metric evaluation of AgNOR in the detection of incipient cellular alte rations. Methods. A morphometric analysis of AgNORs was performed in o ral mucosa epithelium adjacent to squamous cell carcinoma compared wit h normal mucosa epithelium and the carcinomatous parenchyma. Results. Highly statistically significant differences in all 5 AgNOR-related pa rameters assessed were found between normal mucosa and mucosa adjacent to cancer. Conversely, the corresponding nuclear parameters failed to exhibit significant differences. The parameter AgNOR contour index pl otted for individual cases affords a cutoff value that could prove use ful in identifying epithelia at early stages of transformation. Conclu sions. AgNOR evidenced significant variations in epithelium adjacent t o oral squamous cell carcinoma, which did not exhibit morphologic sign s of atypia. Based on this study, AgNOR would be a quantitative, discr iminative aid, easy to monitor in a pathology laboratory, in detecting incipient cellular alterations. These findings contribute to the issu e of early diagnosis and to the knowledge of tumoral growth.