CONSULTATION CORNER Section Editor: David J. Dabbs What is the Role of Cytopathologists in Stereotaxic Needle Biopsy Diagnosis of Nonpalpable Mammographic Abnormalities? W. Fraser Symmans, M.D., 1 * Joan F. Cangiarella, M.D., 1 Susan Gottlieb, M.D., 2 Gillian M. Newstead, M.D., 2 and Jerry Waisman, M.D. 1 The popularity of screening mammography has led to increased detection of mammographic lesions that require pathologic diag- nosis. Stereotaxic needle biopsy techniques to sample such lesions can be used to either identify those lesions that require excision from those that can be followed, or to confirm a mammographic impression of malignancy prior to excision. Stereotaxic core bi- opsy (SCBX) and stereotaxic fine needle aspiration (SFNA) have rarely been directly compared. For this review we undertook a uniform re-analysis of the data that was presented in the published studies of SFNA and/or SCBX. The main endpoint was the negative predictive value (NPV) that measures the frequency that a benign diagnosis is truly benign. There was variability in NPV (likely due to sampling methods) and specific aspects of sampling techniques are discussed. The NPV was compared to indicators of selection of lesions to biopsy (frequency of invasive cancer in the study pop- ulation), mammographic characteristics (masses or microcalcifi- cations), and the reported nondiagnostic rates. The general con- clusion is that SFNA and SCBX are equivalent in accuracy, with considerable variability that reflects the types of lesions that are selected for biopsy and the thoroughness of sampling. For SFNA studies, nondiagnostic rates were inversely related to NPV, and therefore have clinical implications. This was not shown for SCBX studies, and probably reflects an inability to correctly identify non-representative tissue biopsies. The main advantage for includ- ing cytologic methods with stereotaxic breast biopsy is immediate sample assessment, and this advantage can also be applied to core needle procedures. Diagn. Cytopathol. 2001;24:260 –270. © 2001 Wiley-Liss, Inc. Key Words: stereotaxic needle biopsy (SFNA); mammography; core biopsy (SCBX); mammotome (SMBX); advanced breast bi- opsy instrument (ABBI) Why Bother With Stereotaxic Needle Biopsies? Advances in screening and diagnostic mammography dur- ing the last decade have improved the detection of precan- cerous lesions and early breast cancer. 1,2 However, most mammographic lesions that are identified will prove to be of no pathologic significance and do not warrant surgical ex- cision. 3–6 Diagnostic imaging techniques further demon- strate that certain findings of screening mammography are artifacts, and so do not require further evaluation. 7 Typi- cally, spot compression mammographic views of a sus- pected lesion “squash out” an artifactual density produced by overlapping breast parenchyma. Supplemental breast ultrasound may demonstrate that a mass lesion is likely to be malignant or is a simple cyst or fibroadenoma. Biopsy is recommended if the nature of a lesion remains in doubt after diagnostic imaging studies. The American College of Radiologists recently published a standardized system for scoring the level of suspicion for lesions that are viewed by mammography: the Breast Imaging Reporting and Data system (BI-RADS). 8 The lesion is allocated a BI-RADS score between 1 (benign) and 5 (probably malig- nant). Generally, lesions of category 1 or 2 require only follow-up, whereas lesions of categories 3–5 are evaluated further by needle biopsy or surgical excision. In the USA, most (75–90%) mammary lesions that undergo needle bi- opsy are diagnosed as benign. 3–6 The majority of these women are advised to undergo routine mammographic and clinical follow-up after a benign needle biopsy. The main clinical value of needle biopsy techniques is, therefore, to 1 Department of Pathology, New York University Medical Center, New York, New York 2 Department of Radiology, New York University Medical Center, New York, New York * Correspondence to: W. Fraser Symmans, M.D., now at the Department of Pathology, Box 85, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030. E-mail: fsymmans@mdanderson.org Received 9 June 2000; Accepted 31 July 2000 260 Diagnostic Cytopathology, Vol 24, No 4 © 2001 WILEY-LISS, INC.