Fibroadenoma in oral contraceptive users: a histopathologic evaluation of epithelial atypia.

We have reviewed histologically a series of 120 fibroadenomas which formed part of the case material from a previous case-control epidemiological investigation of the relationship between oral contraceptive use and breast disease. We evaluated the epithelial component of the fibroadenoma for degree of cytologic atypia. This study indicates that the reduced risk for fibroadenoma among long-term users of oral contraceptives does not vary according to the degree of epithelial atypia present. This is in contrast to our previously reported findings for fibrocystic disease, in which the decreased frequency of occurrence of the disease in long-term users of oral contraceptives was found only for cases with no minimal epithelial atypia.