NUCLEOLAR ORGANIZER REGIONS IN ADENOID CYSTIC CARCINOMA OF THE SALIVARY-GLANDS

In this study of proliferative activity of adenoid cystic carcinomas ( ACCs) with different histological patterns, the argyrophilic staining method of nucleolar organizer regions (AgNORs) was applied to paraffin sections from 25 tumors. Sixteen of the neoplasms showed a mixture of different histological patterns in the same section. The AgNOR number s in the different histological pattern areas in the same tissue secti ons of all 16 tumors were lowest in the cribriform, intermediate in th e trabecular, and highest in the solid pattern areas. The mean AgNOR n umber was highest in the solid pattern (3.33 +/- 0.52), and lowest in the cribriform pattern (2.12 +/- 0.43). The results show the order of proliferative activity in the different histological pattern areas of ACC, and explain the previous clinical finding that the prognosis of A CC is poorest in solid pattern ACCs. AgNOR staining appears to be a us eful technique for evaluation of the proliferative activity of each hi stological pattern area of ACC, expecially when there are different hi stological pattern areas in the same tissue section.