Echogenic Rind on Breast Ultrasound Associated with High Specificity for Malignancy

An echogenic rind on breast ultrasound may be a significant indicator of malignancy, according to a new study involving over 500 women.

For the retrospective study, recently published in the American Journal of Roentgenology, researchers reviewed breast ultrasound findings for 511 women (mean age of 52) who had BI-RADS category 4 or 5 presentations revealing suspicious masses. There was a total of 583 suspicious masses in the cohort and 249 were malignant, according to the study.

Based on the assessments of two reviewing radiologists, the study authors determined that echogenic rind on breast ultrasound had a 51 to 58 percent sensitivity along with an 81 to 85 percent specificity for malignancy.

The researchers noted that echogenic rind was present in 53 to 62 percent of invasive ductal carcinoma (IDC) cases, 53 to 57 percent of cases involving invasive lobular carcinoma (ILC) and 18 to 24 percent of ductal carcinoma in situ (DCIS) cases.

“Among breast malignancies, the finding’s frequency was greater in invasive than noninvasive cancers as well as in cancers with luminal A than luminal B or basal-like molecular subtypes. Additionally, inclusion of the rind in ultrasound-based mass measurements decreased the extent of underestimation with respect to pathologic tumor size measurements from surgical resection. These results provide insights into the clinical implications of an echogenic rind on ultrasound, which in turn could inform further diagnostic workup and preoperative decision-making,” wrote lead study author Derek L. Nguyen, M.D., who is affiliated with the Department of Radiology at the Duke University School of Medicine in Durham, N.C., and colleagues.

For the purposes of the study, the researchers noted the presence of echogenic rind required > 25 percent circumferential extent. While extending the circumferential extent threshold to complete led to a 10 to 13 percent increase in specificity, the study authors also noted accompanying declines in sensitivity ranging between 38 to 43 percent.

Noting that the echogenic rind finding — currently defined as partial or complete surrounding of a mass by a thick hyperechoic band along with disruption of surrounding tissue texture — may be included in a forthcoming sixth edition of BI-RADS, the researchers posited that the 25 percent circumferential extent threshold may provide optimal diagnostic utility.

“Such observations could help inform the formal definition that is ultimately adopted for an echogenic rind in future BI-RADS editions. For example, the optimal approach may be to define an echogenic rind based on the presence of at least 25% circumferential extent rather than to require a 50%, 75%, or complete circumferential extent,” added Nguyen and colleagues.

(Editor’s note: For related content, see “Abbreviated MRI and Contrast-Enhanced Mammography Provide Fourfold Higher Cancer Detection than Breast Ultrasound,” “GE HealthCare Unveils AI-Powered 3D Ultrasound System for Dense Breasts” and “Can Ultrasound-Based Radiomics Enhance Differentiation of HER2 Breast Cancer?”)

In regard to study limitations, the authors acknowledged that the presence of echogenic rind was only evaluated for BI-RADS category 4 and 5 masses. They also noted that the findings were based on evaluations from two reviewing radiologists from the same facility.