Aneuploidy in sclerosing adenosis may predict an increased risk of malignancy. A study using the AgNOR silver stain

Sclerosing adenosis (SA) of the breast if a disease associated with an increase relative risk of malignancy. The exact incidence and factors influencing malignant transformation in association with SA are not well established. Two counts of the AgNOR silver staining technique have been correlated with ploidy and proliferative activity. The first count which is the mean number of AgNOR granules (mAgNOR), correlates with ploidy. The second count is the percentage of nuclei exhibiting > or = 5 AgNORs/nucleus (pAgNOR) and reflects proliferative activity. The hypothesis in the current study was that aneuploidy, as determined by the AgNOR silver staining technique, may potentially identify lesions of SA with an increased association with malignant breast disease. The AgNOR silver staining technique was performed on 69 cases of SA with the application of the two counts. Of these cases 53 were not associated with malignancy and 16 were associated with synchronous or metachronous carcinoma of the breast, these being 11 cases of invasive ductal carcinoma (IDC), four cases of ductal carcinoma in situ (DCIS) and one case of lobular carcinoma in situ (LCIS). The patient ages ranged from 27 to 84 years (median 53 years) with a median follow up of 28 months. Six of the 53 cases of SA no associated with malignancy (11%) had aneuploid mAgNOR counts of > or = 2.4 whereas 12 of the 16 cases associated with carcinoma (80%) had such counts (p < 0.0005). This included nine cases of IDC, two cases of DCIS and the case of LCIS. Of the six aneuploid cases not associated with malignancy, two cases showed cytological atypia, one case was associated with atypical ductal hyperplasia and one case was seen in a leukemic patient who had received chemotherapy and radiation therapy. The pAgNOR counts showed a statistically less significant correlation with malignancy (p < 0.03). These findings suggest that aneuploidy, measured by the AgNOR silver stein, seen in SA may help identify lesions with a higher relative risk of being associated with breast carcinoma and hence that may require more aggressive management than diploid ones.