Image-guided percutaneous biopsy has largely replaced excisional biopsy of mammographic lesions. Vacuum-assisted core biopsy has improved sampling of such lesions. The objectives of this study were to define the accuracy of the vacuum-assisted 11-gauge stereotactic core biopsy in sampling of atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) and to define histologic and mammographic features of target lesions, which predict sampling errors.Methods:
Between October 1996 and March 2000, 1341 patients underwent stereotactic 11-gauge vacuum-assisted biopsy. Patients with ADH or DCIS were encouraged to undergo excisional biopsy.Results:
Surgical excision of 37 ADH lesions revealed 5 missed DCIS lesions and 1 missed invasive cancer. Twelve of 91 DCIS lesions were upstaged to invasive cancer upon excision. The underestimation rate was highest in patients with DCIS when the target lesion for biopsy was a zone of calcifications >1.5 cm. No correlation existed between the histologic features of DCIS lesions diagnosed by stereotactic biopsy and the presence of infiltrating disease on excision.Conclusions:
Vacuum-assisted 11-gauge stereotactic core biopsy understages 13.2% and 13.5% of DCIS and ADH lesions, respectively. In patients with DCIS found by stereotactic biopsy, a target zone of calcifications >1.5 cm is associated with a higher underestimation rate of infiltrating disease.