Progression of Multiple Myeloma or Plasma Cell Leukemia

**Semantic type:** Finding

**Definition:** Progression of multiple myeloma or plasma cell leukemia requires any one or more of the following: Increase of 25% or more from baseline in: serum M-component with an absolute increase 0.5 g/dL or more (for progressive disease, serum M-component increases of 1 g/dL or more are sufficient to define relapse if the starting M component is 5 g/dL or more); urine M-component with an absolute increase 200 mg. or more/ 24 hours; for recipients without measurable serum and urine M-protein levels: the difference between involved and uninvolved free light chain levels (absolute increase more than 10 mg/dL); bone marrow plasma cell percentage (absolute percentage 10% or more); definite development of new bone lesions or soft tissue plasmacytomas, or definite increase in the size of any existing bone lesions or soft tissue plasmacytomas; development of hypercalcemia (corrected serum calcium more than 11.5 mg/dL or 2.65 mmol) that can be attributed solely to the plasma cell proliferative disorder. Progression of disease requires two consecutive assessments made at any time before classification as disease progression, and/or the institution of any new therapy.

**Synonyms:** - Progressive Disease of Multiple Myeloma or Plasma Cell Leukemia