[Study of silver binding nucleolar organizer regions (AgNORs) in proliferative lesions of bronchi, colon and...

Silver-binding nucleolar organizer regions (AgNORs) were studied in the proliferative lesions and in normal tissue of bronchi, colon and thyroid gland. In the histopathological samples AgNORs were seen as blacks dots more or less scattered within nuclei. The investigated parameters included the number and area of AgNOR-dots, the number of AgNOR clusters, the ratio of AgNOR dot area to the nuclear area and the area of single AgNOR dots. The measurements were done with the help of semiautomatic computer image analysis. In thyroid the differences between proliferative lesions and also normal gland tissue were strongly marked in the number of clusters. Low values were typical for oxyphilic neoplasms and papillary carcinomas--in oxyphilic neoplasms single clusters within nuclei were seen. In bronchi and colon the differences between proliferative lesions and also normal tissue were strongly marked in the number and area of dots. High values were typical for squamous cell carcinomas or adenocarcinomas whereas low values were in small cell carcinomas. The ratio of dot area to nuclear area and the area of single dots were similar in various lesions and also in the normal tissue of thyroid, bronchi and colon. This study have shown that in the proliferative lesions of bronchi, colon and thyroid AgNOR values, particularly the number and area of AgNOR dots or the number of the AgNOR clusters show differences and are related with the type of tissue, type of lesion or their malignant character and are also related with the size of nuclei.