Atypical duct hyperplasia of the breast in young females.

Atypical duct hyperplasia of the breast is an unusual finding in the adolescent or young adult female. We report nine young women, ages 18-26 years (mean 21) with atypical duct hyperplasia. Clinical presentation was either breast hypertrophy treated by reduction mammoplasty (five patients) or a thickening or mass that was examined via biopsy (four patients). No focal abnormalities were present on gross examination other than two fibroadenomas in one patient. Microscopically, isolated hyperplastic ducts were scattered in a background of prominent stromal collagenization. Each case showed a continuum of ductal changes, from partial to complete involvement by micropapillary and laciform epithelial hyperplasia, which was sometimes markedly atypical. In four, lobules were poorly developed or not present in the available sections. During a follow-up of 5-68 months (mean 39), none developed breast carcinoma. Much longer follow-up is needed to determine if young women with atypical duct hyperplasia are at increased risk for subsequent development of breast carcinoma. Presently, no surgical or medical intervention is recommended, but such patients should perform breast self-examination and be monitored regularly by a physician.