Screening-detected calcified and non-calcified ductal carcinoma in situ: Differences in the imaging and histopathological features

Abstract

To compare the imaging and histopathological features of screening-detected calcified and non-calcified ductal carcinoma in situ (DCIS). The study involved 217 DCIS cases in 212 asymptomatic patients admitted between May 2007 and December 2010. All lesions were divided into calcified and non-calcified DCIS according to the presence of calcifications on mammography. Two radiologists reviewed the findings from mammography, ultrasound, and magnetic resonance imaging (MRI) in consensus according to the Breast Imaging Reporting and Data System. The histopathological features of the lesions were obtained from medical records. Statistical comparisons were performed using the chi-square, Fisher's exact test, and intraclass correlation coefficient (ICC) analyses. On mammography, most non-calcified DCIS presented as either a false-negative finding (49%) or mass lesion (30%), whereas most calcified DCIS (68.5%) presented as calcification alone (p<0.001). At ultrasound, all of the non-calcified DCIS appeared as a mass, whereas 62% of the calcified DCIS appeared as a mass (p<0.001). At histopathology, high nuclear grade (p=0.017), necrosis (p<0.001), positive progesterone receptor (p=0.027), and presence of the HER-2/neu oncogene (p<0.001) were more common in the calcified DCIS than in the non-calcified DCIS. There were no significant differences in the MRI features between the two groups. The ICC values of the non-calcified and calcified DCIS between predicted tumour size and pathologic size were 0.625 versus 0.705 for mammography, 0.801 versus 0.552 for ultrasound, and 0.760 versus 0.767 for MRI. Screening-detected calcified and non-calcified DCIS have different mammographic and sonographic features. Ultrasound could be helpful to predict the pathological size of the non-calcified DCIS.