2020 Volume 45 Issue 4 Pages 394-404
Purpose: To investigate ultrasonographic findings of mammary fibromatosis.
Subjects and Methods: Seventeen lesions (eight patients) histopathologically diagnosed with mammary fibromatosis between January 2000 and December 2018 were examined. For mass lesions, the ultrasonographic findings that were determined are as follows: shape, margin, echogenic halo, internal echo, posterior acoustic features, architectural distortion, echogenic foci, and vascularity. For non-mass abnormalities, the findings that were evaluated are as follows: duct abnormalities, hypoechoic areas in the mammary gland, architectural distortion, multiple small cysts, echogenic foci without a hypoechoic area, posterior acoustic features, and vascularity.
Results and Discussion: Of the 17 lesions, 9 were mass lesions, whereas the other 8 were non-mass lesions. All nine mass lesions had an irregularly shaped and ill-defined hypoechoic mass with posterior acoustic shadowing and whirling architectural distortion. An echogenic halo was detected in only one lesion. All eight non-mass lesions showed an ill-defined hypoechoic area with posterior acoustic shadowing and architectural distortion. Of the 17 architectural distortions, 15 demonstrated twisted and swirling architectural distortion, reflecting the histopathological findings of collagenous fibrous tissues that were thrust into the surrounding breast tissue rather than retracted. Although vascularity was identified in 13 of the 16 lesions in which Doppler sonography was performed, blood flow was not abundant in most cases but rather only partial. These findings were similar to those of scirrhous carcinoma or invasive lobular carcinoma; however, the characteristic ultrasonographic findings of mammary fibromatosis were the absence of an echogenic halo; inclusion of a hyperechoic area that continued into the surrounding breast tissue, reflecting the involved breast tissue; and the accompaniment of a twisted and swirling architectural distortion. Younger age was also helpful for the diagnosis. Because metachronous and synchronous bilateral occurrences were observed in four and two patients, respectively, the contralateral breast should also be examined.
Conclusion: Characteristic ultrasonographic findings of mammary fibromatosis include an ill-defined hypoechoic mass or hypoechoic area with posterior acoustic shadowing, hyperechoic area connected to the surrounding breast tissue, and whirling architectural distortion, without an echogenic halo.
