Gastric carcinoma: histopathology, immunocytochemistry and variations of nucleolar organizer regions (AgNORs)

The true nature of Nucleolar Organizer Regions Argyrophilic related proteins (AgNORs) is still unknown, but there is wide agreement that their number expresses the nuclear activity. We undertook an investigation on fifty cases of gastric adenocarcinomas (previously grouped morphologically into well and poorly differentiated) applying together with the AgNOR technique, histochemical (Alcian Blue/PAS, High Iron Diamine) and immunohistochemical methods (alpha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme). AB/PAS was more frequently positive in well-differentiated adenocarcinomas. On the contrary HID was prevailingly positive in poorly differentiated adenocarcinomas. alpha 1 ACT was expressed in all poorly differentiated adenocarcinomas and in a few well-differentiated adenocarcinomas, whereas lysozyme and alpha 1 AT were never expressed. The AgNORs were more numerous, larger, clumped and irregular in shape in poorly differentiated adenocarcinomas. Considering that alpha 1 ACT reactivity seems to be well correlated with survival and given that there is a good correlation between the aforementioned characteristics of AgNORs and the expression of alpha 1 ACT, our investigation suggests that the four techniques used in this study could be useful to predict the prognosis.