A Prospective Study about Abnormal Ductal Dilatations without Associated Masses on Breast US. What is the Significance for us?

Rationale and Objectives: Ductal changes are described as a finding of surrounding tissues in breast masses according to the Breast Imaging Reporting and Data System - Ultrasound. However, ductal changes are often found as an isolated finding without a mass on ultrasound. The purpose of this study was to investigate the clinical significance of abnormal ductal dilatations without masses on breast ultrasound. Materials and Methods: From August 2006 to August 2008, 75 pathologically verified pure ductal dilatations without associated masses on breast ultrasound were collected. Ultrasound findings including the diameter and length of the duct, the presence of ductal wall thickening and intraluminal content, the echo pattern of intraluminal content, and distribution were evaluated. The ultrasound findings were correlated with clinical and pathologic features, and radiologic differences between benign and malignant lesions were assessed using Fisher's exact tests. Results: Of the 75 cases with abnormal ductal dilatations, seven (9%) were malignant, and four (5%) were atypical ductal hyperplasia. Ductal dilatations were longer in malignancies than in benign lesions (P < .05). Ductal wall thickening was more frequent in malignancies (100%) and atypical ductal hyperplasia (50%) than in other benign lesions (3%) (P < .05). Hypoechoic intraluminal content was more common in malignancies (86%) and atypical ductal hyperplasia (50%) than in other benign lesions (8%) (P < .05). Furthermore, a segmental distribution was more frequent in malignancies (43%) than in benign lesions (1%). Clinical symptoms were also frequent in malignancies (86%) than in benign lesions (4%) (P < .05). Conclusions: Abnormal ductal dilatations without masses have a 9% malignancy rate, and these would be recommended to undergo biopsy as suspicious abnormalities according to Breast Imaging Reporting and Data System - Ultrasound. Ultrasound has an essential role in the assessment of abnormal ducts for distinguishing benign and malignant ductal changes.