Objective: To analyze the mammographic and ultrasonographic findings of ductal carcinoma in situ (DCIS) and determine the sensitivity in Thai women.

Material and Method: Mammograms and bilateral whole-breast ultrasonograms of 37 proven cases of DCIS were reviewed. The former was assessed for microcalcifications and soft tissue densities while the latter was evaluated for masses and thickened ducts. Ultrasonography was used to spot the areas to visualize soft tissue densities in mammogram.

Results: Mammography detected 22 cases of DCIS having pure microcalcifications, eight cases with mixed microcalcifications and soft tissue densities, six cases with pure abnormal soft tissue densities and one case showing negative finding. The ultrasonography detected 13 cases showing masses, seven cases as showing thickened ducts and 17 cases as negative findings.

Conclusion: Microcalcifications are characteristic findings in mammogram accounting for 81% of DCIS in the present study. Ultrasonography shows abnormalities including mass and thickened duct lesions in 54% of DCIS. The combined modalities can give the detection of abnormalities in 97% of DCIS.

Keywords: Mammography, Ultrasonography, Breast, Ductal carcinoma in situ