[Whole organ giant section histopathologic studies on breast cancer. III. Benign lesions in cancerous breast and near the tumor areas].

From April 1988 to January 1989, histopathologic studies of whole organ subserial sections was done in 200 mastectomy specimens of female breast carcinoma. The results indicated that extensive cystic proliferative disease (66%) and ductal epithelial hyperplasia (65%) were present in the cancer-bearing breasts. Most of them often distributed in two or more quadrants. Atypical hyperplasia was seen in 48% of all specimens, among them 54.2% was found in two or more quadrants. The incidence of atypical epithelial proliferation near the multiple primary foci (57%) was significantly higher than that near the main primary tumor (28.5%). Atypical hyperplasia adjacent to the tumor areas was commonly found more severely and had a tendency to transform into the malignancy. The authors concluded that the breast carcinoma is not an isolated lesion but a disease which arises from extensive epithelial hyperplasia of the breast. The malignant transformation usually appear in multiple sites within the same breast.