Imaging features of noncalcified DCIS

Abstract

Objective: To illustrate the radiological features of noncalcified DCIS (NCDCIS) on mammography, ultrasound and MRI. To highlight the role of MRI in determining extent of disease. Introduction: DCIS accounts for 20% screen-detected cancers and 5% of symptomatic cancers. Eighty to 90% present mammographically as microcalcifications, but 10 to 20% are noncalcified and can be mammographically occult. With reported re-excision rates as high as 65% for breast-conserving surgery in DCIS, accurately determining disease extent on preoperative imaging is important. Methods: Imaging of 117 patients with pure DCIS from 2007 to 2011 was reviewed retrospectively. Fifteen patients with NC-DCIS were identified. Imaging findings were compared with disease extent on postoperative histology. Results: NC-DCIS appeared as follows. Mammography: occult 33%, diffuse increased breast density 33%, focal architectural distortion 13%, wellcircumscribed lesion 13%, tubular ductal density 7%. Ultrasound: occult 7%, intraductal lesion 13%, microcystic lesion 13%, solid lesion 53%, illdefined echo poor focus 13%. MRI: nonmass-like nodular enhancement in a ductal, segmental or regional distribution 83%, amorphous nonmasslike enhancement 17%. MRI best depicted the true extent of disease. Conclusion: Recognition of these imaging features is important for accurate surgical planning. MRI has an important role in accurately delineating disease extent and should be considered in treatment planning for NC-DCIS.