experience with the advanced breast biopsy instrumentation abbi system background the advanced breast biopsy instrumentation abbi system is designed to excise nonpalpable breast lesions under stereotactic control we report our experience with special regard to the histological evaluation of marginspatients and methods breast biopsies using the abbi system were performed on 101 patients with microcalcifications in histologicallyproven breast cancer a reexcision was performedresults malignant lesions were found in thirteen patients 3 clis 5 dcis 5 invasive ductal carcinoma the margins were positive in two specimens with dcis in subsequent lumpectomies one patient with invasive cancer had residual intraductal cancer all the patients with dcis had residual cancer even those with negative margins of the abbispecimen only minor complications were observed with the abbi procedureconclusion the abbi system is a safe minimally invasive stereotactic breast biopsy technique it saves open biopsies in atypical hyperplasia and clis in cases of dcis or invasive cancer reexcision is inevitable