Diagnostic Criteria for Multiple Myeloma

Definition and Diagnostic Criteria

• Hypercalcemia in multiple myeloma is defined as a corrected serum calcium level greater than 11.5 mg/dL (2.9 mmol/L) and is considered a defining diagnostic criterion for the disease, according to the International Myeloma Working Group criteria 1, 2, 3
• Hypercalcemia is one of the four CRAB criteria (hypercalcemia, renal insufficiency, anemia, bone lesions) used to diagnose symptomatic multiple myeloma requiring treatment, as recommended by the International Myeloma Working Group 2, 3
• The threshold for hypercalcemia in multiple myeloma is defined as serum calcium >11.5 mg/dL (2.9 mmol/L) according to the International Myeloma Working Group criteria, and treatment is typically initiated when calcium levels exceed 11.0 mg/dL 1, 3, 4

Disease Progression

• Development of hypercalcemia (>11.5 mg/dL) not attributable to other causes is considered a criterion for disease progression in multiple myeloma, according to the National Comprehensive Cancer Network 1, 5