Hiroshi Nishie

Argyrophilic nucleolar organizer regions of breast tumors: Assessment of aspirated cytological materials

To investigate the correlation between argyrophilic nucleolar organizer regions (Ag-NORs) and the malignant potential of breast tumors, we analyzed Ag-NORs of cytological specimens obtained from 190 patients with various types of breast disease by preoperative aspiration biopsy. The average number of Ag-NORs per nucleus was defined as the Ag-NOR score. The Ag-NOR score was 5.7 ± 1.7 in the group of women with breast carcinoma (n = 70), 2.6 ± 0.4 in the group with fibroadenoma (n = 54) and 2.9 ± 0.6 in the group with mastopathy (n = 66). The level was significantly higher in breast carcinoma than in each benign disease (p < 0.001 in both cases). The score was 6.5 ± 2.3 in the group with four or more metastatic lymph nodes (n = 21), 5.2 ± 1.2 in the group with one to three metastatic lymph node (n=10) and 5.1 ± 1.1 in that with no metastatic lymph node (n = 39); the score was significantly (p < 0.05) higher in the groups with four or more metastatic lymph nodes than in the ohter groups, respectively. Thus, a correlation was observed between the Ag-NOR score and lymph node status. These data suggest that a higher Ag-NOR score reflects high-grade malignancy.