Correlation of Mammography, Ultrasound and Sonoelastographic Findings With Histopathological Diagnosis in Breast Lesions

Abstract

Introduction Breast masses range from inflammatory and benign to malignant lesions, varying in different age groups and clinical presentations. Breast imaging techniques leading to prompt and specific diagnosis have been a lifesaver for millions around the globe saving them undue mental stress in inflammatory lesions and preventing early death in case of neoplasms. Here, we compare mammography, ultrasonography (US) and ultrasound elastography in the screening and diagnosis of breast lesions and the usefulness of strain ratio as a non-invasive tool in diagnosing breast malignancies. Aims and objectives Determining the characteristics of breast lesions on imaging by mammogram, ultrasonography, elastography, calculating strain ratio and correlating them with histopathology. To further estimate the advantages and limitations of one modality over the other in the evaluation of breast lesions. Methods The study was done over a duration of 18 months from November 2019 to June 2021 at JSS Medical College and Hospital, Mysuru. In this prospective study, 73 female patients with palpable breast lesions were evaluated using mammography, US and sonoelastography and were co-related with histopathological findings. Results This study has proved that the use of ultrasound elastography has higher sensitivity (91.67% with strain ratio kept at 3) in detecting malignant lesions when compared with x-ray mammography and ultrasonography having a sensitivity of 87.88% and 90.91%, respectively. Our study confirmed that there is a correlation between strain ratio and histopathological findings and that the strain ratio has high sensitivity in diagnosing and differentiating malignant breast lesions. Conclusions Mammography, US and sonoelastography when combined together are helpful in characterization and management of breast lesions. This helps to avoid unnecessary invasive interventions. The specificity of the study in detecting malignant lesions was comparable with that of histopathological analysis.

Keywords: bi-rads; breast cancer; elastography; mammography; shear-wave elastography; ultrasound.

Figure 1. (a-d) A 65-year-old female with palpable mass in the right breast.

(a,b) The mammogram (MLO and CC views) shows a large irregular radio-dense mass with irregular and partially indistinct margins. (c) USG B mode image shows an irregularly shaped hetero-echoic lesion with irregular margins and intrinsic vascularity. (d) Histopathology image shows a feature of invasive ductal carcinoma.

Figure 2. Elastography of invasive ductal carcinoma (same patient images shown in Figure 1).

USG elastography showing Tsukuba elasticity score of 4 with high elasticity strain ratio of 5.51

Figure 3. (a-d) A 43-year-old female with a palpable mass in the left breast.

(a,b) Mammogram (CC and MLO views) shows a large radio-dense mass with an irregular shape, margins, and few speculations with evidence of adjacent skin thickening and nipple retraction. (c) USG B mode image shows a hypo-echoic lesion with irregular margins and intrinsic vascularity. (d) Histopathology image suggestive of metaplastic carcinoma showing tumor cells arranged in a solid pattern with pleomorphic vesicular nuclei, prominent nucleoli, and moderate cytoplasm. Areas of chondroid differentiation and necrosis with tumor giant cells and lymphoplasmacytic infiltrates were seen.

Figure 4. Elastography of metaplastic carcinoma (same patient images as in Figure 3).

USG elastography images showing Tsukuba elasticity score of 4 with high elasticity strain ratio of 7.7

Figure 5. A 41-year-old female with a palpable mass in the left breast.

(a) USG B mode image shows a well-circumscribed hypoechoic mass lesion with slightly lobulated margins. (b) USG Elastography images show Tsukuba elasticity score of 2 with high elasticity strain ratio of 2.31. (c) Histopathology image suggestive of fibroadenoma.

Figure 6. Co-ordinates of the curve in ROC for strain ratio