Fibroadenoma of the female breast. Some epidemiologic surprises.

In a study of 70 cases of fibroadenoma of the female breast, two ages of peak incidence were recorded, one of them in the late 20s to early 30s and a second in the late 40s to early 50s. At the time of diagnosis, the lesions usually were less than 3.0 cm in diameter. Almost two thirds of the tumors were situated in the lateral quadrants of the breast. Incidence of fibroadenoma was significantly higher among parous females tham among nulliparas. Review of family histories showed a remarkably high incidence of breast disease of all types in the mothers and sisters of the patients studied. An inordinately high proportion of patients under 40 years of age were nonwhite. Recurrences and multiple lesions were much more frequent in patients over 40. "Recurrences" are undoubtedly serial presentations of multicentric lesions.