Serum Beta-2 Microglobulin Pretreatment Level
**Note 1:** Serum microglobulin is part of the Revised International Staging (RISS). Use the cut points listed in the table below regardless of the lab's reference range.
**Note 2:** Record this data item based on a blood test performed at diagnosis (pre-treatment). In the absence of the lab test, a physician's statement of the exact value can be used. Use the highest value available.
**Note 3:** If there is no mention of the serum beta-2 microglobulin, code 9.
**Note 4:** If Schema Discriminator 1: Plasma Cell Myeloma Terminology is coded to 1 or 9, code 5.