Vacuum-assisted biopsy diagnosis of atypical ductal hyperplasia and patient management

This study sought to evaluate the accuracy of vacuum-assisted biopsy (VAB) in the diagnosis of atypical ductal hyperplasia (ADH) by determining the rate of VAB underestimation compared with definitive histology. In addition, an attempt was made to identify parameters that could help determine the most appropriate patient management.

We retrospectively reviewed 1,776 VAB procedures performed between November 1999 and January 2008 for suspicious subclinical breast lesions visible only at mammography. A total of 177 patients with a VAB diagnosis of pure ADH were studied. Patients with a diagnosis of ADH associated with other lesions (lobular intraepithelial neoplasia, papilloma), atypical lobular hyperplasia, lobular carcinoma in situ and any lesions with a microhistological diagnosis other than ADH were excluded. Mammographic appearance of lesions was as follows: 152 mostly clustered microcalcifications (86%); five opacities with microcalcifications (3%); 12 single opacities (3%); and eight parenchymal distortions (4%), of which five were without and three were with microcalcifications. In cases underestimated by VAB, we evaluated the extent of ADH within ducts and lobules. Based on results, patients were subdivided into two groups: ≤2 ADH foci; >2 ADH foci. Patients were subdivided into two groups: one was referred for surgery and the other for follow-up care. The decision to either perform or not perform surgery was based on combined analysis of the following parameters: patient age; risk factors in the patient's history; mammographic extent of microcalcifications; complete excision of microcalcifications at VAB; and final Breast Imaging Reporting and Data System (BI-RADS) assessment.

In the first group (n=98), comparison of microhistology with final histology revealed that 19 cases of ADH had been underestimated by VAB. In the second group (n=79), six cases of ADH showed progression of the mammographic abnormality, which was subsequently confirmed by surgical biopsy.

The most relevant parameters affecting the decision to proceed to surgical excision were lesion diameter >7 mm on mammography, >2 ADH foci, incomplete removal of the calcifications and a family and/or personal history of breast cancer. Although there are no definite mammographic predictors of malignancy, a radiological assessment of suspicious lesion in the presence of an additional equivocal parameter always warrants surgical management.