Adequate Histologic Sampling of Breast Magnetic Resonance Imaging--Guided Core Needle Biopsy (Report‪)‬

Within the last 10 years, contrast-enhanced magnetic resonance imaging (MRI) of the breast has gained recognition as a valuable adjunct to mammography and ultrasound in the detection of breast lesions that might otherwise be clinically, sonographically, and mammographically occult. There is general agreement among investigators that the sensitivity of breast MRI is excellent, ranging between 88% and 100%, with more variable specificity ranging from 37% to 97%. Despite the use of several criteria in the classification of MRI-detected lesions and the interpretation of contrast-enhancement kinetics, suspicious BIRADS (breast imaging reporting and data system) IV and V lesions still require histologic diagnosis. Two different approaches to the histologic verification of MRI-detected breast lesions are feasible. The first is MRI-guided wire-localized open breast biopsy. Although open breast biopsy yields good results, the surgery is costly, invasive, and associated with a certain perioperative risk. As an alternative, percutaneous breast biopsy techniques under MRI guidance have been developed. Under mammographic and sonographic guidance, percutaneous biopsy techniques have already been carefully evaluated and have been shown to be safe and accurate methods. When compared with open breast biopsy, percutaneous biopsy is less invasive, faster, and can be performed at lower cost.1 This category of specimens currently accounts for approximately 20% to 30% of the breast needle core biopsies at our institution, and usually the amount of tissue removed is 3 to 4 times greater than that removed with stereotactic or ultrasound breast needle core biopsies. Thus, the routine examination of these specimens (cutting, staining, and reading of 4 levels, ie, 4 slides of tissue), necessitates a considerably greater amount of work by the pathology laboratory personnel (histology technicians as well as resident and attending pathologists). To decrease the cost and workload to our laboratory, while maintaining the same quality of patient care, we retrospectively reviewed all of our breast MRI-guided core needle biopsies to determine the optimal number of levels needed for accurate diagnosis.