Background: The treatment policy for ductal cancer in situ (DCIS) of the breast greatly depends on the spreading diagnosis. However, a problem is that we cannot compare imaging findings with the histopathology of DCIS. The purpose of this study was to investigate the histopathological characteristics of DCIS and the association with imaging findings.
Method: Subjects were 185 patients from Tokai University Hospital, diagnosed with DCIS from April 2005 to December 2010. A positive finding on ultrasonography was defined as Breast Imaging Reporting and Data System (BI-RADS) of US category 3 or above, in mammography it was Japan Breast Cancer Society category 2 or above, and in MRI it was BI-RADS-MRI category 3 or above. Histopathologically, we re-classified flat and/or low papillary DCIS into type 1; papillary and/or cribriform DCIS into type 2; and comedo and/or solid DCIS into type 3.
Results: The clinical characteristics and association between imaging findings and histopathological classification of the 3 subtypes of DCIS are summarized as follows: (1) histopathologically, in type 3, there was a higher frequency of necrosis and calcification in the ducts of DCIS (χ²), p < 0.001), the number of dilated periductal capillaries was greater than in type 1 (p = 0.023), and the distribution of DCIS was concentrated in type 3 (p = 0.020); (2) on ultrasonography, type 3 was easier to detect than type 1 (p = 0.008); (3) on mammography and MRI, there were no significant differences between type 1 and type 3. The histopathological characteristics of small (< 10 mm) DCIS and DCIS that cannot be detected by ultrasonography or MRI were also discussed.
Conclusion: When carrying out spreading diagnosis of DCIS, we need to keep the histopathological type in mind and interpret the imaging findings comprehensively.
Keywords: Breast; Ductal carcinoma in situ (DCIS); Histopathology; Imaging findings.