Segmental Breast Calcifications

Abstract

B reast calcifications related to both benign and malignant causes are commonly seen on screening mammography. Additional views, such as spot magnification craniocaudal and 90° lateral, are typically required to further characterize these calcifications. Depending on their morphology and distribution, calcifications can be stratified into different risk categories: benign (BI-RADS 2), with recommendation for continued routine screening; probably benign (BI-RADS 3), warranting follow-up imaging to assess for stability; and suspicious morphology or distribution (BI-RADS 4 or 5), which necessitates core biopsy for definitive diagnosis. The distribution of calcifications within the breast, which has an important association with relative risk of malignancy, can be described as scattered, regional, grouped, or segmental. Diffuse calcifications throughout both breasts have a low association with malignancy. Regional calcifications occur in a volume of tissue greater than one quadrant, do not correspond with the expected distribution of a ductal unit, and are not typically associated with malignancy. Depending on morphology, grouped calcifications may be characterized as benign, although in many cases they may have suspicious morphology warranting biopsy. Segmental calcifications are best described as calcium deposits that conform to the expected distribution of one or more ducts and their branches, usually radiating toward the nipple. They can have a branching appearance or cover a triangular region, with the most acute angle pointing to the nipple. Whereas segmental calcifications often can be characterized as benign, microcalcifications following a segmental distribution are often suspicious for malignancy because of their anatomic relationship with the ductal system. This article focuses on both benign and malignant causes of segmental calcifications (Table 1).