Diagnosis of Ductal Carcinoma in situ: Role of Additional Breast Sonography

ABSTRACT

PURPOSE: To verify the role of additional sonography on routine mammograms in the diagnosis of ductal carcinoma in situ (DCIS). MATERIALS AND METHODS: Between 2005 and 2008, a total of 105 breasts belonging to 102 patients were diagnosed with DCIS by surgery. Preoperative ultrasound and mammographic findings and reports using BI-RADS were retrospectively reviewed and analyzed. In both mammogram and ultrasound, BI-RADS categories 1, 2, and 3 were regarded as negative results and categories 4 and 5 as positive results. We analyzed the frequency in which additional ultrasound examinations aided in the diagnosis in each mammographic finding. RESULTS: Out of the 105 cases, 96 showed positive results on a mammogram and 9 cases showed negative results. Clustered microcalcifications, positive mammographic findings, were found most often (64/96, 66.67%). In those cases, ultrasound examinations gave no additional information, but did enablesonographically-guided biopsies in 38. In the 32 cases with other positive mammographic findings, ultrasound examinations were helpful in 15 cases. Of the 9 cases showing negative results on a mammogram, 8 cases were correctly diagnosed with DCIS because of the additionally-performed ultrasound examination, but 1 case returned a false negative on both the mammogram and ultrasound examination. CONCLUSION: Additional sonography contributes to a diagnosis of DCIS in patients with negative mammographic findings, nonspecific mammographic findings, or multifocal lesions.