Diagnostic criteria for symptomatic myeloma and suggested initial workup. BUN, blood urea nitrogen; FDG-PET/CT, 18F-fludeoxyglucose–positron emission tomography/computed tomography; FISH, fluorescence in situ hybridization; LC, light chain; LDH, lactate dehydrogenase; LLN, lower limit of normal; MRI, magnetic resonance imaging; ULN, upper limit of normal; WBMRI, whole-body magnetic resonance imaging.