Application of Elastography in the Diagnosis of Idiopathic Granulomatous Mastitis (IGM): A Systematic Review

Abstract

Context: Idiopathic granulomatous mastitis (IGM) is a benign inflammatory condition of the breasts with an unknown etiology, which can mimic breast cancer on conventional ultrasound. Other imaging modalities, such as mammography and magnetic resonance imaging, cannot efficiently differentiate this condition from malignancies. Elastography is a novel imaging technique used to evaluate tissue elasticity. Objectives: This systematic review aimed to investigate the imaging features of IGM on elastography and also to determine whether this modality is useful for distinguishing IGM from other breast malignancies. Materials and Methods: A comprehensive literature search was conducted across several databases, including Medline, Embase, Cochrane Library, Scopus, and Web of Science, in October 2022. The Joanna Briggs Institute (JBI) critical appraisal tool was used for the quality assessment of the studies. Results: After screening 851 articles, seven studies investigating ultrasound elastography were found to meet the inclusion criteria. Regarding the quantitative findings, both the strain ratio and shear wave velocity were observed to be higher in malignant masses as compared to IGM. Additionally, qualitative scoring systems, such as the Tsukuba and Tozaki classifications, assigned higher scores to malignant lesions. Five of the included studies in this review proposed a specific cut-off point for differentiating IGM from malignancies, using either shear wave velocity, strain ratio, or elasticity scores. In four of the studies, these criteria exhibited sensitivity and specificity of approximately 90%. Conclusion: The current findings suggest that ultrasound elastography can serve as a valuable tool for distinguishing IGM from breast malignancies. By potentially reducing the number of unnecessary tissue biopsies, this modality may lead to a more efficient patient evaluation process.