Sonographic Findings And Pathological Features Of Pure Ductal Carcinoma In Situ Without Microcalcifications On Mammography

Objective:To investigate the characteristic sonographic findings and pathological features of breast pure ductal carcinoma in situ(DCIS)without microcalcifications on mammography(MG).Methods:We retrospectively reviewed the MG findings of 101 cases of pure DCIS and 40 cases of DCIS without microcalcifications on MG were studied.We analyzed the sonographic findings of 40 lesions according to mass or nonmass abnormality.The pathological subtypes and nuclear grades of these cases were also analyzed and the results were correlated with pathological features.Fisher exact test was used to compare the differences of the sonographic accuracy rate,sonographic microcalcification rate,pathological nuclear grade and subtype rate between mass and nonmass abnormalities.Results:No abnormal finding was shown in sixteen cases(40%)and one case(2.5%)in 40 cases of pure DCIS without microcalcifications on MG by MG and Ultrasonography(US),respectively.The most common sonographic findings of DCIS without microcalcifications on MG were masses(75%,30/40),with round/oval and irregular shape,microlobulated margin,heterogeneous hypoechogenicity and isoechogenicity,and without posterior acoustic features.Ductal dilatations and heterogeneous isoechogenicity were present in most nonmass US findings of DCIS without microcalcifications on MG(22.5%,9/40).The ultrasonographic microcalcifications were found in 5 cases of pure DCIS without microcalcifications on MG.The most common pathological features of DCIS without microcalcifications on MG were medium-low nuclear grade(85%,34/40)and noncomedo(87.5%,35/40).The difference of US accuracy rate in mass and nonmass abnormalities was statistically different(73.7% and 33.3%,P=0.047).The differences of US microcal-cification rate,pathological subtype and nuclear grade were not significant(P=0.572,1.000,0.070).Conclusions:The mass appearance and noncomedo medium-low nuclear grade were most common sonographic findings and pathological features of pure DCIS without microcalcifications on MG respectively.Ultrasonography should be an adjunctive tool to increase the sensitivity of mammography in breast pure DCIS diagnosis.