Abstract P1-01-09: Ductal carcinoma in situ: A comparative study between histopathological characteristics and imaging findings
Authors: Tang X , Yamashita T , Kumaki N , Tokuda Y , Masuda S 
Published: May 2016

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.

Methods: Subjects were 128 patients from Tokai University Hospital, diagnosed with DCIS. A positive finding on ultrasonography (USG) was defined as Breast Imaging Reporting and Data System (BI-RADS) of US category 3 or above, in mammography (MMG) 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 DCIS into 3 subtypes.

Table. Histopathological classification of the 3 DCIS subtypesSubtypesArchitectures of DCISType 1Flat and/or micropapillaryType 2Cribriform and/or papillaryType 3Solid and/or comedo, solid or comedo with any other architecture patterns, e.g. solid and cribriform or papillary, etc.

The microscopic examination items included the nuclear grade, necrosis and calcification, stromal reactions surrounding DCIS, distribution of DCIS, and with or without adenosis or other benign changes in the background breast. The automated image analysis using figures captured from virtual system are planned to evaluate concentration of DCIS distribution.

Results: 1) The clinical characteristics and association between imaging findings and histopathological classification of the 3 subtypes of DCIS are summarized as: a) Histopathologically, in type 3, there was a higher frequency of necrosis and calcification in the ducts of DCIS (χ2, p&lt;0.001), the number of dilated peri-ductal capillaries was greater than in type 1 (p=0.023), and the distribution of DCIS was concentrated in type 3 (p=0.020); b) In imaging findings, type 3 was easier to detect than type 1 on USG (p=0.008), but there were no significant differences in MMG and MRI. 2) The 14 DCIS cases that could not be detected by USG, showed slight edematous or myxoid change in the stroma histopathologically (p&lt;0.001), and were less likely to be detected by MRI (p=0.004). 3) The 6 MRI un-detected cases were less likely to be detected by USG (p=0.004), and the occurrence of adenosis or other benign changes in the background breast interfered with MRI (p=0.010). Peri-ductal capillaries seemed to be an important factor for MRI detection (p=0.007). 4) The results of automated image analysis will be presented.

Conclusion: USG imaging reflected the histopathological subtypes of DCIS, myxoid changes of the stroma, and the concentration of DCIS ducts. MRI was correlated with the peri-ductal capillaries of DCIS and the changes in the background breast, while MMG can make up for the shortcomings of USG and MRI. It is important for us to keep the histopathological type in mind and interpret the imaging findings comprehensively, when we do a spreading diagnosis of DCIS.

Citation Format: Tang X, Yamashita T, Kumaki N, Tokuda Y, Masuda S. Ductal carcinoma in situ: A comparative study between histopathological characteristics and imaging findings. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-01-09.