Application of argyrophilic nucleolar organizer region (AgNOR) staining for cytology of biliary tract carcinomas.

Purpose/background: Increased numbers of argyrophilic nucleolar organizer region (AgNOR) dots reflect higher proliferating activity of malignant cells.

Methods: To determine whether AgNOR staining is suitable for cytology of bile in biliary diseases as an ancillary diagnostic method, we examined the mean number of AgNOR dots (MNA) in cells of both bile smear and tissue sections in 14 benign biliary diseases and 25 malignancies of the biliary tract. The malignant diseases consisted of 11 gallbladder cancers, 10 bile duct cancers, and 4 ampulla cancers in patients who underwent surgical resection.