Sonographic Findings of High‐Grade and Non–High‐Grade Ductal Carcinoma In Situ of the Breast

Objective. The purpose of this study was to differentiate between high‐grade and non–high‐grade ductal carcinoma in situ (DCIS) of the breast on sonography. Methods. From October 2003 to August 2009, 76 DCIS lesions in 73 women who underwent sonography and mammography were included in this study. Lesions were confirmed by mastectomy, breast‐conserving surgery, or surgical biopsy. Images were analyzed by 2 radiologists with consensus and were correlated with histologic grades. Results. Of the 76 lesions, 44 were classified as high‐‐grade and 32 as non–high‐grade DCIS. Fifty‐seven lesions (75.0%) were identified on sonography, which revealed a mass in 30 cases, microcalcifications in 20, ductal changes in 4, and architectural distortion in 3. All cases with false‐negative findings on sonography (n = 19) showed microcalcifications on mammography. On sonography, masses were more frequently found in non–high‐grade (62.5%) than high‐grade DCIS (22.7%; P < .01). No significant difference was seen in the sonographic features of masses between high‐grade and non–high‐grade DCIS. Microcalcifications were more common in high‐grade (43.2%) than non–high‐grade (3.1%) DCIS (P = .02). Most sonographically visible microcalcifications had associated findings such as ductal changes (n = 11), a mass (n = 7), or a hypoechoic area (n = 5). The detection rate of microcalcifications on sonography was higher in high‐grade (62.9%) than non–high‐grade DCIS (25.0%; P = .023). Conclusions. Microcalcifications with associated ductal changes (11 of 31 [35.5%]) were the most common sonographic findings in high‐grade DCIS. An irregular hypoechoic mass with an indistinct and microlobulated margin (13 of 26 [50.0%]) was the most frequent finding in non–high‐grade DCIS.