Dilated duct pattern at mammography.

Purpose: To determine the importance of a dilated duct pattern at mammography.

Materials And Methods: Mammograms obtained in 46 women with histopathologically proved, asymmetrically dilated ducts were retrospectively studied. The laterality and location of the asymmetrically dilated duct, the presence of branching, and associated findings such as microcalcifications, nipple discharge, and interval change were evaluated.

Results: Eleven patients (24%) had malignant results (ductal carcinoma in situ or invasive ductal carcinoma). Among these, six (54%) had suspicious microcalcifications. Nonsubareolar location and interval change are significant (P = .04) variables associated with malignancy.

Conclusion: Mammographic asymmetrically dilated ducts in a nonsubareolar area that are associated with interval change, suspicious microcalcifications, or both warrant biopsy.