Nuclear morphometry of benign and malignant breast lesions.

The mean nuclear area (MNA) of mammary gland epithelium was measured in 403 breast specimens, comprising 239 invasive carcinomas, 49 carcinomas in situ, 45 cases of fibrocystic disease (f.c.d.) with intraductal epithelial hyperplasia, and 60 cases of f.c.d. without intraductal hyperplasia. Normal breast tissue adjacent to other benign or malignant lesions was measured in 170 specimens. Statistical analysis revealed no difference between the MNA of invasive ductal carcinoma and ductal carcinoma in situ. The MNA of lobular and ductal carcinomas were significantly different. Significant differences were also found between ductal carcinoma and the two classes of f.c.d. The MNA of f.c.d. with and without intraductal hyperplasia were also significantly different, the former having the highest MNA. All breast lesions showed MNA significantly higher than that of normal breast epithelium. These findings show that there is a gradual increase in MNA from the baseline value of normal breast epithelium, via fibrocystic disease without and with intraductal proliferation to invasive carcinomas. Measurement of MNA may aid in pinpointing cases of intraductal epithelial hyperplasia with malignant potential.