Stereotactic breast biopsy: indications and results.

Imaging-guided breast biopsy performed with large-core needles can accurately diagnose most breast pathologies, often allowing a diagnosis to be made more quickly and less expensively than with surgical biopsy. Major complications, such as hemorrhage and infection, are extremely rare, although post-biopsy ecchymosis and tenderness are not unusual. Because less tissue is removed, post-biopsy cosmetic deformity does not occur. Stereotactic biopsy is performed by triangulating the position of a breast lesion and by obtaining views angled equally off a central axis. This can be done using dedicated tables or add-on equipment. Stereotactic core biopsy has a reported accuracy of at least 90%. All lesions for which biopsy would ordinarily be recommended are amenable to stereotactic techniques, but those near the chest wall or in the axilla may be more difficult to biopsy with some equipment. Lesions characterized by calcifications are sometimes more difficult to sample. A biopsy diagnosis of ductal atypia, because of its histologic heterogeneity, requires surgical excision to exclude coexistent carcinoma, which has been found in half of women at subsequent surgical excision. A core biopsy diagnosis of ductal carcinoma in situ does not preclude the discovery of invasive carcinoma at surgery. In rare instances, the small tissue volume removed at stereotactic biopsy does not permit a final diagnosis to be made; this occurs most commonly when differentiating phyllodes tumor from fibroadenoma.