Hypoechoic lesion with pseudo-distortion on breast ultrasound: Normal anatomical variants?

Abstract

Purpose: We have encountered cases of hypoechoic lesions on breast ultrasonography that were diagnosed as normal anatomic variants based on further examinations or follow-up, despite the presence of distortion-like findings. In this study, we investigated what additional findings should be considered for such hypoechoic lesions to avoid unnecessary follow-up examinations. Subjects and Methods: In 27 patients with localized distortions suggestive of breast cancer during ultrasound screenings performed between April 2013 and March 2015, a total of 31 hypoechoic lesions were evaluated retrospectively. Seven of these 31 lesions did not show any obvious lesions on further examination, and 24 lesions did not require further examination and were followed up by repeat ultrasound. We retrospectively examined the ultrasound findings in these patients and confirmed their subsequent outcome. Results and Discussion: The common findings based on the 31 lesions were: (1) Its localization was not consistent with Cooper’s ligaments in some cases, (2) unbranched vessels were observed on color Doppler imaging, and (3) no strain reduction was observed in any cases in which strain elastography was performed. These lesions were mostly located in the lateral part of the breast. No proliferative lesions were found among the four lesions in which we performed fine-needle aspiration biopsy or core needle biopsy. During a median follow-up of 60 months, no cancer was found in any of the cases, including those under scrutiny. Conclusion: Our study suggests that some of lesions with distortion-like findings resembling breast cancer on ultrasound are normal anatomic variants. It seems extremely important to understand such lesions to avoid unnecessary scrutiny and biopsy.