Demystifying Breast Disease Markers.

Breast imaging radiologists regularly perform image-guided biopsies of suspicious breast lesions based on features that are associated with a likelihood of malignancy ranging from 2% to greater than 95% (Breast Imaging Reporting and Data System categories 4 and 5). As diagnostic partners, pathologists perform histopathologic assessment of these tissue samples to confirm a diagnosis. Correlating the imaging findings with the histopathologic results is an integral aspect of multidisciplinary breast care. Assessment of radiologic-pathologic concordance is vital in guiding appropriate management, as it enables identification of discordant results, minimizing the chance of misdiagnosis. Undersampling can lead to false-negative results, with the frequencies of false-negative diagnoses varying on the basis of multiple factors, including biopsy type (eg, core needle, vacuum-assisted needle), needle gauge, and type of lesion sampled at biopsy (ie, mass, calcifications, asymmetry, architectural distortion). Improving a radiologist's knowledge of macroscopic and microscopic breast anatomy and more common breast diseases and their expected imaging findings ensures more accurate radiologic-pathologic correlation and management recommendations. The histopathologic and molecular characteristics of biopsy-sampled breast lesions aid in making an accurate diagnosis. Hematoxylin-eosin staining provides critical morphologic details, whereas immunohistochemical staining enables molecular characterization of many benign and malignant lesions, which is critical for tailored treatment. The authors review commonly encountered benign and malignant breast diseases, their corresponding histopathologic phenotypes, and the histopathologic markers that are essential to clinching the diagnosis of these entities. As part of a multidisciplinary team that provides optimal patient care, radiologists should be knowledgeable of the foundations of histopathologic diagnosis and the implications for patient management to ensure appropriate radiologic-pathologic concordance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Sonographic Evaluation of Clinically Palpable Breast Cancers Invisible on Mammography.

The purpose of this study was to determine the utility of sonography in the evaluation of palpable breast cancers invisible on mammography. A retrospective review of the pathology department's database was used to identify patients with palpable breast cancers. Consecutive patients that had excision between January 1992 and September 1997 were included. Mammograms and breast ultrasounds were reviewed retrospectively and correlated with pathologic and surgical findings. During the study period 298 women presented with a palpable breast cancer for imaging at our institution. Of these, 38 cancers (12.8%) were not seen on mammography. In 32 patients where no mammographic abnormality was found, ultrasound was able to detect a mass corresponding to the area of clinical concern. Histologic tumor types included 30 invasive ductal carcinomas, 5 ductal carcinomas in situ, and 3 invasive lobular carcinomas. Mammographic density was mild with scattered fibroglandular densities in 2 (5%), heterogeneously dense in 12 (32%), and extremely dense in 24 (63%). Thirty-one masses (97%) were hypoechoic and 1 (3%) was echogenic. Lesion margins were irregular in 23 (72%), lobulated in 5 (16%), and well-circumscribed in 4 (12%). In this group of patients the combination of mammography and ultrasound of the mass demonstrated 99% of the palpable cancers. In patients presenting with a breast mass on physical examination in whom mammography fails to demonstrate an abnormality, supplemental ultrasound is helpful in most instances to further characterize the lesion.