Papillary breast lesions on contrast-enhanced ultrasound: morphological enhancement patterns and diagnostic strategy.

Objectives: To identify features which determine the papillary nature of breast lesions by contrast-enhanced ultrasound (CEUS) based on morphological and pathological correlations, and predict which papillomas are malignant.

Methods: A retrospective review of 47 papillary lesions and 51 hypervascular benign abnormalities was performed. Enhancement patterns and diagnostic performance of CEUS were assessed.

Results: The most frequent finding in papillary lesions was perilesional linear ductal enhancement (87.2%) followed by heterogeneous enhancement (80.9%), and the presence of perfusion defects (66%). Among all CEUS morphological descriptors, a perilesional linear ductal enhancement pattern was the most effective feature to discriminate between papillary and hypervascular benign lesions. Using this criterion, the positive and negative predictive value for papilloma were 100% and 89.5%, respectively. A perilesional linear ductal pattern correlated with a ductal origin. The distinctive features associated with atypical or malignant papillomas were non-confluent enhancement, late overall wash-out, the presence of regional perfusion defect, clumped vascular pattern, and the presence of peripheral radial or penetrating vessels. The sensitivity, specificity, and positive and negative predictive values for predicting malignancy were 91.7%, 82.6%, 84.6% and 90.5%, respectively.

Conclusions: CEUS provided characteristic enhancement patterns which could be helpful for identifying papillary lesions and for predicting potentially malignant papillomas.

Key Points: Papillary breast lesions display a characteristic appearance on CEUS. Adding CEUS to conventional US helps identify the papillary nature of papillomas. CEUS may be helpful for predicting potential malignancies among papillomas.