Ductal carcinoma in situ of the breast: correlation between mammographic and pathologic findings.

OBJECTIVE: Ductal carcinoma in situ shows heterogeneous clinical behavior and response to treatment depending on its pathologic features. The aim of this study was to correlate the radiologic and pathologic features of ductal carcinoma in situ of the breast. Differences, if present, may allow refinement of diagnosis and selection of treatment options.
MATERIALS AND METHODS: The mammograms of 128 patients with ductal carcinoma in situ of the breast were analyzed by a radiologist who knew that the patients had ductal carcinoma in situ but had no other pathologic information. The radiologic and pathologic features of subgroups characterized according to cell size and presence of necrosis were then compared. Statistical comparisons were made by using the chi 2- and Fisher's exact tests.
RESULTS: Patients with small-cell ductal carcinoma in situ more commonly have a normal mammogram (28% vs 6%, respectively, p < .001) or an abnormal mammogram without calcification (42% vs 5%, respectively, p < .001) than do patients with large-cell ductal carcinoma in situ. Among patients with abnormal mammographic findings, calcification is present in 58% of those with small-cell ductal carcinoma in situ, compared with 95% of those with large-cell ductal carcinoma in situ (p < .001). No significant differences were found in the calcification morphology of small- and large-cell ductal carcinoma in situ. These features were seen more commonly in ductal carcinoma in situ with necrosis than in ductal carcinoma in situ without necrosis, respectively: abnormal mammographic findings (95% vs 73%, p < .001), calcification (96% vs 61%, p < .001), calcification with a ductal distribution (80% vs 45%, p < .005), and rod-shaped calcification (83% vs 45%, p < .001). An abnormal mammogram without calcification (39% vs 4%, p < .001) or predominantly punctate calcification (36% vs 13%, p < .05) was seen more commonly in ductal carcinoma in situ without necrosis than in ductal carcinoma in situ with necrosis, respectively.
CONCLUSION: We have shown that the radiologic features of ductal carcinoma in situ vary according to cell size and the presence of necrosis in particular. Necrosis has been found to be a feature of more biologically aggressive in situ breast cancer, so these findings may be of practical value in deciding the management of indeterminate calcification clusters and whether to offer breast conservation.