Findings
Figure 1: MLO view of left breast of year 2017 (figure 1a ) and 2019 (figure 1b) reveals a new focal asymmetry in upper half of the left breast (white arrow). Figure 2 – (a) The spot compression MLO view shows persistence of asymmetry on spot compression view. (b) Ultrasound reveals a small heterogeneous mass with mixed hyperechoic and hypoechoic areas in the region of mammographic focal asymmetry. Figure 3: (a, b)The mass detected on ultrasound is confirmed to be a true correlate of the mammographic abnormality by injecting a small amount of contrast under ultrasound guidance and a subsequent mammogram is taken. Ultrasound guided biopsy was performed due to increased suspicion of malignancy as the focal asymmetry was an interval appearance in a postmenopausal woman who has previously been treated for contralateral breast cancer, irregular margins of the focal asymmetry on the spot compression view and the presence of mixed hyperechoic and hypoechoic components on ultrasound. Final histopathology - DCIS.
Answer
(1) BI-RADS 4b (2) Possible differential diagnoses for hyperechoic masses include both benign and malignant entities. However, the interval appearance of focal asymmetry in a patient who has previously been treated for contralateral breast cancer and the presence of mixed hyperechoic and hypoechoic components on ultrasound increases the suspicion for malignancy.
Discussion
Most of the breast malignancies have hypoechoic appearance on ultrasound. Although extremely rare, hyperechoic breast malignancies do exist (1). Although the echo pattern contributes with other feature categories to the assessment of a breast mass, echogenicity alone has little specificity. Therefore, every echogenic breast mass should not be discarded as benign. Patient demographics, interval appearance, suspicious mammographic findings, axillary lymphadenopathy and clinical history must also be taken into account (2). Hyperechoic masses should be evaluated by using the same characteristics that are used to assess hypoechoic breast masses and should be assigned an appropriate ACR BI-RADS category. Differential diagnoses for malignant hyperechoic lesions include invasive lobular carcinoma and invasive ductal carcinoma, DCIS, metastasis, lymphoma, and sarcoma (3). A comprehensive ultrasound scan should be performed with a careful search for the presence of suspicious sonographic features such as inhomogeneity in the echogenic pattern, non-parallel orientation, posterior shadowing, and irregular margins to lower the threshold for biopsy and avoid delay in diagnosis (4). As in our case, the interval appearance of focal asymmetry in a postmenopausal woman with a prior history of breast cancer is a significantly worrisome feature and should supersede less suspicious ultrasound appearance.
Reference
1. Linda A, Zuiani C, Lorenzon M, et al. Hyperechoic lesions of the breast: not always benign. Am J Roentgenol 2011;196:1219–1224. 2. Echogenic Breast Masses at US: To Biopsy or Not to Biopsy? Yiming Gao, Priscilla J. Slanetz, and Ronald L. Eisenberg. RadioGraphics 2013 33:2, 419-434. 3. Hyperechoic Lesions of the Breast: Radiologic-Histopathologic Correlation, Beatriz Adrada, Yun Wu, and Wei Yang. American Journal of Roentgenology 2013 200:5, W518-W530. 4. Tiang, S., Metcalf, C., Dissanayake, D. and Wylie, E. (2016), Malignant hyperechoic breast lesions at ultrasound: A pictorial essay. J Med Imaging Radiat Oncol, 60: 506-513. https://doi.org/10.1111/1754-9485.12468.
