Objective: The comedo subtype of ductal carcinoma in situ (DCIS) is more aggressive than noncomedo DCIS. Differentiating noncomedo DCIS from the more aggressive comedo subtypes on mammography would allow the surgeon to excise comedo DCIS with a wider margin. The mammographic features of microcalcifications associated with nonpalpable comedo DCIS, noncomedo DCIS and benign disease were compared to determine the usefulness of this finding in diagnosis of comedo DCIS.
Methods: The authors retrospectively and blindly reviewed the mammograms of 91 consecutive patients in whom DCIS was diagnosed by needle localization and surgical excision. An equal number of cases of benign microcalcifications were also reviewed. Microcalcifications were evaluated with respect to pattern, density, configuration and size. These results were correlated with the pathologic findings.
Results: All 16 cases (100%) of linear branching calcifications and 34 (80%) of the 43 cases of linear calcifications were associated with comedo DCIS (p < 0.001). The number of calcifications, the density and the size of clustering were not diagnostic of comedo DCIS. Granular calcifications occurred in noncomedo DCIS and in benign disease associated with noncalcifying DCIS.
Conclusion: Comedo DCIS is suggested by the presence of linear and linear branching microcalcifications on mammography.