Mixed solid and cystic masses (MSCMs) of the breast contain variable proportions of cystic and solid elements or thick septa. Although MSCMs have been divided into groups on the basis of the proportions of their cystic versus solid components, no group can be definitively categorized as benign or probably benign on the basis of the amount of solid component present according to biopsy outcomes in case studies. Therefore, MSCMs are typically classified as suspicious lesions (BI-RADS category 4) and, with rare exceptions, require an ultrasound (US)-guided biopsy of the solid component and clip placement. A wide variety of benign and malignant pathologies may manifest as an MSCM, and patient history and multimodality imaging can guide decision-making. US is the mainstay modality for characterizing MSCMs, but mammography (MG) may identify additional features of an MSCM, such as rim calcification or internal fat, which can support diagnosis of a benign lesion and potentially avoid image-guided biopsy. MRI generally is not used to characterize MSCMs, but many patients diagnosed with malignancies presenting as MSCMs undergo MRI as part of an evaluation of the extent of disease. This Pictorial Essay will review the salient imaging features of benign and malignant types of MSCMs on MG, breast US, and breast MRI.
DO et al. (Thu,) studied this question.