Noncalcified ductal carcinoma in situ: Imaging and histologic findings in 36 tumors

Objective. The purpose of this study was to evaluate imaging findings in noncalcified ductal carcinoma in situ (DCIS) and to compare histologic findings between noncalcified and calcified DCIS. Methods. From January 2005 to May 2008, 195 patients with pathologically confirmed DCIS were recruited. Among these, 36 patients (18%) had noncalcified DCIS. We retrospectively reviewed their imaging findings according to the American College of Radiology Breast Imaging Reporting and Data System. We also reviewed pathologic reports for all patients with DCIS to obtain information on the histologic type, nuclear grade, and biological markers. Results. Among the 36 patients with noncalcified DCIS, 21 (58%) were symptomatic. On mammography, 25 patients (69%) showed abnormal findings, and 11 patients showed false-negative findings. On sonography, 29 of 36 patients (81%) showed a mass, whereas the remaining 7 patients (19%) showed nonmass lesions. The sonographic findings for the masses were variable: 25 of 29 masses (86%) were irregular in shape; 14 of 29 (48%) showed indistinct margins; and 9 (31%) were angular or spiculated. The orientation of the mass was not parallel in 6 of 29 cases (21%). Two of 29 masses (7%) showed an echogenic halo at the lesion boundary. Noncalcified DCIS tended to have a nonhigh nuclear grade and was frequently the noncomedo type. In addition, c-erb-B2 was more commonly expressed in calcified DCIS. Conclusions. Imaging findings for noncalcified DCIS are relatively nonspecific and are frequently similar to those of invasive malignancy. This knowledge may be useful for detecting noncalcified DCIS, planning treatment, and predicting the prognosis.