Diagnostics for multiple myeloma.

Multiple myeloma (MM) has been diagnosed based on the International Myeloma Working Group (IMWG) diagnostic criteria since 2003. In 2014, the IMWG updated these diagnostic criteria to add three specific biomarkers, i.e., 1) Clonal bone marrow plasma cell percentage ≥60%; 2) Involved: uninvolved serum free light chain ratio ≥100; 3) >1 focal lesion on MRI studies, based on CRAB features (hypercalcemia, renal failure, anemia, and bone lesions). An early diagnosis of MM can be made, allowing timely anti-MM treatment, in patients with the ultra-high-risk smoldering form of this disease. This review focuses on the new IMWG diagnostic criteria for MM and evaluation of patients newly diagnosed with MM.