Atypical ductal hyperplasia: histologic underestimation of carcinoma in tissue harvested from impalpable breast lesions using 11-gauge stereotactically guided directional vacuum-assisted biopsy.

OBJECTIVE: This review was undertaken to determine the reliability of the histologic diagnosis of atypical ductal hyperplasia (ADH) made from tissue obtained by 11-gauge stereotactically guided directional vacuum-assisted biopsy of impalpable breast lesions. MATERIALS AND METHODS: Four hundred twenty-two 11-gauge stereotactically guided vacuum-assisted breast biopsies were performed at our institution between November 5, 1996, and June 30, 1998. Biopsies were performed with the patient prone on a dedicated stereotactic biopsy table. A directional vacuum-assisted biopsy device was used. Eight to 24 cores (mean, 13.4) were harvested from each lesion. Radiography of core specimens was performed in cases in which the target lesion contained microcalcifications. Twenty (4.7%) of the 422 biopsies yielded a histopathologic diagnosis of ADH. Surgical excision of 16 of the 20 lesions was subsequently performed. We compared the histopathologic results of the core extracted and the corresponding surgically excised tissue. RESULTS: Of the 16 surgically excised lesions, four (25.0%) retained the diagnosis of ADH. Four (25%) were upgraded to carcinoma: Two (12.5%) were ductal carcinoma in situ without comedonecrosis, one (6.3%) was invasive carcinoma, and one (6.3%) was tubular carcinoma. Of the remaining eight surgically excised lesions, six (37.5%) were interpreted as benign fibrocystic changes with ductal hyperplasia without atypia, and two (12.5%) were interpreted as lobular carcinoma in situ. CONCLUSION: Because ADH was underdiagnosed in 25% of the lesions, we recommend that surgical excision be performed whenever ADH is found in tissue obtained from 11-gauge directional vacuum-assisted breast biopsy.