Skeletal changes in plasma cell dyscrasias

Background Plasma cell dyscrasias are a spectrum of diseases characterized by clonal plasma cell proliferation. Important entities within this group are monoclonal gammopathy of unknown significance, smoldering multiple myeloma, and symptomatic multiple myeloma. Purpose The goal of this review is to illustrate plasma cell dyscrasia imaging findings of bone and bone marrow as seen on whole-body computed tomography (CT) and magnetic resonance imaging (MRI) and to discuss the relevance of imaging for management of patients with plasma cell dyscrasias. Materials and methods Selective literature search with analysis of dedicated original research articles and reviews and discussion of clinical guidelines. Results Diagnostic classification of plasma cell dyscrasias is based on the SLiM-CRAB criteria. CT primarily represents imaging of mineralized bone to show osseous end organ damage by detecting osteodestruction. MRI is primarily used for bone marrow imaging to detect diffuse or focal bone marrow infiltration, even in the absence of bone destruction. Different patterns of bone marrow infiltration can be distinguished. Treatment response is associated with characteristic imaging signs of lesion regression. Conclusion Imaging plays a prominent role in treatment stratification of patients with plasma cell dyscrasia at first diagnosis and during follow-up.