Ductal enhancement on MR imaging of the breast.

OBJECTIVE

The purpose of this study was to determine the prevalence and positive predictive value of ductal enhancement among MR imaging-detected breast lesions that had biopsy and to assess the histologic findings associated with ductal enhancement.

MATERIALS AND METHODS

Retrospective review was performed of 427 nonpalpable, mammographically occult lesions that had MR imaging-guided needle localization and surgical biopsy. Lesions were reviewed by one radiologist who was unaware of the histologic outcomes and were classified according to a standardized lexicon. MR imaging and histologic findings of ductal enhancing lesions were reviewed.

RESULTS

Ductal enhancement accounted for 88 (21%) of 427 lesions and 88 (59%) of 150 nonmass lesions. Histologic finding in these 88 lesions were ductal carcinoma in situ (DCIS) in 18 (20%); infiltrating carcinoma in five (6%), including three with DCIS; lobular carcinoma in situ (LCIS) in nine (10%); atypical ductal hyperplasia in eight (9%); and benign in 48 (55%). Among the 48 benign lesions, the dominant histologic findings were fibrocystic change (n = 16); ductal hyperplasia (n = 8); fibrosis (n = 8); postbiopsy change (n = 5); benign breast tissue (n = 3); sclerosing adenosis (n = 2); and single cases of fibroadenoma, fibroadenomatoid change, lymph node, mastitis, papilloma, and radial scar. Factors associated with a trend toward a higher frequency of carcinoma included clumped enhancement (p = 0.05) and synchronous ipsilateral cancer (p = 0.07).

CONCLUSION

Ductal enhancement accounted for 21% of MR imaging-detected lesions that had biopsy and had a positive predictive value of 26%. Differential diagnosis of ductal enhancement includes carcinoma (usually DCIS); atypical ductal hyperplasia; LCIS; and benign findings such as fibrocystic change, ductal hyperplasia, and fibrosis.