Clinically occult ductal carcinoma in situ detected with mammography: analysis of 100 cases with radiologic-pathologic correlation.

One hundred consecutive cases of clinically occult ductal carcinoma in situ (DCIS) detected with mammography were retrospectively analyzed to determine the spectrum of mammographic appearances and to study pathologic correlations. Seventy-two percent of the lesions appeared as microcalcifications, 10% as soft-tissue abnormalities, and 12% as a combination of the two. Six percent of lesions were found incidentally in the biopsy specimen. On the basis of mammographic measurements, 22% of the lesions were 5 mm or smaller, and 75% were 20 mm or smaller. Thirty-five percent of the microcalcification clusters were categorized as predominantly casts (linear), 52% as granular, and 13% as granular with several casts. Related pathologic features included the location of the tumor within the ductal system, pattern of growth (histologic subtype), amount and distribution of calcium formation, and presence or absence of reactive changes. Women aged 49 years or less with DCIS were more likely to have microcalcifications and less likely to have a soft-tissue mass than women aged 50 years or more (P = .04). The authors conclude that there is a wide spectrum of mammographic appearances of clinically occult DCIS.