Imaging Findings in Papillary Breast Lesions: An Analysis of Ductal Findings on Magnetic Resonance Imaging and Ultrasound.

PURPOSE: This study aims to analyze the imaging features of dilated ducts or ductal extension/relation of masses detected by ultrasound (US) and magnetic resonance imaging (MRI) and to correlate the results obtained through these 2 different imaging methods. Furthermore, the ability of the ductal relation pattern in differentiating benign and malignant lesions was explored.

METHODS AND MATERIALS: Magnetic resonance imaging and US findings of 56 patients who had a pathologic diagnosis of papillary lesion were examined. Ductal findings were classified into four types for both imaging methods: intraductal form, extraductal form, mixed form, and no ductal relation. The correlation between MRI and US was then analyzed with respect to ductal findings. Statistical analyses were performed to determine the value of ductal patterns determined by these 2 imaging methods in the differentiation of benign and malignant papillary lesions.

RESULTS: A total of 56 cases with papillomatosis (n = 11), papillomas (n = 29), and papillary breast carcinomas (n = 16) were included. There was a statistically significant correlation between all ductal patterns on US and the corresponding ductal signs on MRI. Palpable masses were statistically more common in patients with papillary breast carcinoma compared with other groups (P < 0.01). Segmental contrast enhancement occurred at a significantly higher rate in papillary breast carcinoma and papillomatosis patients, as compared with papilloma patients (P < 0.05).

CONCLUSIONS: Actual resolution of MRI is close to that of US in terms of the ability to demonstrate the ductal relation of masses. Segmental contrast enhancement on MRI and nonmass-like heterogeneous hypoechoic area or mass with multiple ductal extensions on US can be used in discriminating benign versus malignant papillary lesions. The absence of ductal sign in MRI indicates benignity.