Comparison of ultrasonographic and mammographic features of extremely rare papillary carcinoma and invasive ductal carcinoma

Introduction:
This study aimed to investigate and compare ultrasonographic and mammographic findings of papillary breast carcinoma and invasive ductal carcinoma in breast masses that were diagnosed as pathological.

Material and methods:
This retrospective study included 88 patients with breast lesions, who underwent ultrasonography, mediolateral oblique-craniocaudal, and tomosynthesis imaging in the Picture Archiving and Communication System between January 2010 and March 2019.

Results:
44 histopathologically diagnosed papillary carcinoma patients and 44 invasive ductal carcinoma patients were divided into groups according to contour, shape, internal structure, calcific-cystic component, echogenicity, posterior acoustic change, skin orientation, and environmental echogenic halo. There was a statistically significant difference between the groups in mammography contour, U/S contour, U/S shape, U/S posterior acoustics, and U/S internal structure. Logistic regression analysis showed that the presence of homogenous appearance (p < 0.001) and absence of shading in the posterior acoustic U/S (p = 0.001) were the most pertinent findings for determining papillary carcinoma. In the U/S, the likelihood of a homogenous tumour being a papillary carcinoma was 16.869 times higher than that of invasive ductal carcinoma, whereas the same probability was 0.1101 times less for a tumour with posterior acoustic shadowing.

Conclusions:
It is challenging to differentiate between invasive ductal carcinoma and papillary carcinoma of the breast without histopathological diagnosis both on ultrasound and mammography. The results of our study demonstrated that the ultrasonographic and mammographic findings of invasive ductal carcinoma and papillary carcinoma were like each other. Therefore, it is still not possible to distinguish between these 2 types of cancer only in accordance with these 2 criteria.