Juvenile fibroadenoma with atypical epithelial hyperplasia.

We studied 49 patients with fibroadenomas with severe atypical epithelial hyperplasia, sometimes suggestive of in situ carcinoma. The term "juvenile fibroadenoma" (JFA) is recommended for these lesions, which occur mainly in adolescent and young women. Twenty-six cases (2%) were obtained through a review of 1,321 consecutive fibroadenomas and 23 were seen in consultation. The 49 patients ranged in age from 10-72 years (average 26 years); 50% were younger than 21 years. This age distribution was significantly lower than that of patients with adult FA (p less than 0.001). Four patterns of atypical epithelial hyperplasia were observed: ductal-laciform, ductal-solid, cystic-papillary and lobular-terminal ductal. Forty-six patients were treated by excision only. Eight years was the average follow-up and 7 years the median follow-up for 28 (57%) patients followed for more than a year (range 1-19 years). Two patients, aged 47 and 59 years at the time of diagnosis of JFA, subsequently developed carcinoma in the contralateral and ipsilateral breast, respectively; all others have remained well. Atypical epithelial proliferation in this setting should be interpreted conservatively. Long-term follow-up is recommended after excision of JFA.