Issues in the interpretation of breast core biopsies.

Core biopsies are now widely used for the nonoperative diagnosis of breast masses and microcalcifications and have replaced fine-needle aspiration (FNA) cytology for most lesions in many centers. In the United Kingdom, a scoring system of 5 reporting categories, B1-B5, has been adopted, which is to some extent similar to that used in the interpretation of breast FNA. This article is based on the practice at Charing Cross Hospital, London, which is a major regional breast screening and treatment center covering the West of London area; as well as on a thorough review of the contemporary literature. It begins by discussing issues related to the adoption of the technique and to handling core biopsies, followed by a brief presentation of the reporting categories. The article then deals with some commonly encountered diagnostic problems.