Association of breast cancer with the finding of atypical ductal hyperplasia at core breast biopsy.

OBJECTIVE: The purpose of the study is to evaluate the prevalence of occult breast carcinoma in surgical breast biopsies performed on nonpalpable breast lesions diagnosed initially as atypical ductal hyperplasia (ADH) by core needle biopsy. BACKGROUND: Atypical ductal hyperplasia is a lesion with significant malignant potential. Some authors note that ADH and ductal carcinoma in situ (DCIS) frequently coexist in the same lesion. The criterion for the diagnosis of DCIS requires involvement of at least two ducts; otherwise, a lesion that is qualitatively consistent with DCIS but quantitatively insufficient is described as atypical ductal hyperplasia. Thus, the finding of ADH in a core needle breast biopsy specimen actually may represent a sample of a true in situ carcinoma. METHODS: Between May 3, 1994, and June 12, 1996, image-guided core biopsies of 510 mammographically identified lesions were performed using a 14-gauge automated device with an average of 7.5 cores obtained per lesion. Atypical ductal hyperplasia was found in 23 (4.5%) of 510 lesions, and surgical excision subsequently was performed in 21 of these cases. In these 21 cases, histopathologic results from core needle and surgical biopsies were reviewed and correlated. RESULTS: Histopathologic study of the 21 surgically excised lesions having ADH in their core needle specimens showed seven (33.3%) with DCIS. CONCLUSIONS: In the authors' patient population, one third of patients with ADH at core biopsy have an occult carcinoma. A core needle breast biopsy finding of ADH for nonpalpable lesions therefore warrants a recommendation for excisional biopsy.