Invasive cribriform carcinoma of the breast: Radiologic and histopathologic features

Background: Invasive cribriform carcinoma (ICC) of the breast is a distinct histologic type of invasive carcinoma that is known to have a relatively favorable prognosis. There is very little information about ICC radiologic findings. Objectives: The purpose of this study is to investigate ICC radiological findings, including those of mammography, sonography, and magnetic resonance imaging (MRI), and histopathological findings. Patients and Methods: Mammography, sonography, and MRI findings of twelve female patients with ICC in our institution were retrospectively reviewed by two radiologists in consensus. Diagnoses were based on surgically resected specimens, and image features were reviewed according to the American college of radiology breast imaging reporting and data system (ACR BI-RADS®) lexicon. Histopathological findings were reviewed by two experienced breast pathologists in consensus. Results: Of the twelve patients, eleven underwent pre-operative mammography, and all underwent pre-operative sonography and MRI. Mammographic findings were mass (n = 8), focal asymmetry (n = 2), or no detectable finding (n = 1). Most masses had irregular shapes, indistinct margins, equal densities to the parenchyma, and no associated calcification. By sonography, all masses were hypoechoic with variable shapes. The margins of the tumors were mostly indistinct. Each tumor was depicted as an enhancing mass with an irregular, oval, or round shape on MRI. Usually, the margins were irregular, and enhancement patterns were type III. On histopathologic examinations, most tumors were grade I, and all were luminal subtype A by immunohistochemical study. Conclusion: ICCs of the breast appear as masses with typical features of malignancy using radiologic techniques. The differences in the radiologic features of invasive ductal carcinoma of no special type, which is the most common invasive breast malignancy, and ICCs are that ICCs usually appear without associated calcifications and show rare spiculation.