Immunohistochemical study of stromal fibronectin in mammary cystic hyperplasia and various breast neoplasms

ABSTRACT

The stromal fibronectin has been studied by indirect immunoperoxidase in benign and malignant human breast lesions. Fibronectin [FN] appeared as fibrils, streaks and granules in the stroma of different breast lesions. The normal breast tissue contained scanty amount of FN which was present at the stromo-epithelial junction of the ductules and lobules. FN was also observed as diffuse fibrils in the stroma and in the waIls of blood vessels, while benign tumours showed only minor difference from normal mammary tissue, malignant mammary neoplasm displayed a different stromal pattern. Moderate and abundant amount of stromal FN were present in 40% of cases of fibrocystic disease, in 40% of benign breast neoplasm and in 80% of the mammary carcinomas. The malignant breast neoplasms contained greater amount of stromal FN .than benign mammary lesions. Scanty amount of stromal FN was noticed in 12% of infiltrating duct carcinomas and in none of the medullary carcinomas. The lobular carcinomas expressed less amount of stromal FN if compared to the infiltrating ductal and medullary types. The grade III duct carcinomas contained plentiful stromal FN .than those of grade II. These findings support the previous studies which suggested that the intense stromal reaction in malignant neoplasms could be attributed to the increasing injury inflicted on connective tissue by infiltrating cancer cells