When should caution be used with regards to histopathologic findings of imaging-guided breast micro- and macro-biopsies?

The development of imaging-guided biopsy techniques has considerably improved the early diagnosis of breast cancers following initial detection by screening. Nevertheless, in a small percentage of cases, histopathologic findings are unsatisfactory owing to false negative errors attributable to operator inexperience or inadequate sample material (this is especially true for microcalcifications with 20% underestimation rates for atypical hyperplasia); repeat biopsy is warranted in such situations. When a discrepancy exists with imaging findings and for cases of atypical epithelial hyperplasia, surgical excision is imperative so as not to overlook or underestimate a malignant lesion. Controversy continues concerning the best approach for radial scars (sclerosing ductal lesions), papillary lesions, atypical lobular hyperplasia and lobular carcinoma in situ: determination of which benign anomalies can merely be followed-up remains a problem. Better awareness of the limitations of percutaneous tissue sampling procedures should lead to refinement of the indications for these techniques and improvement of patient selection and thereby reduce delays in accurate diagnosis.