Monoclonal Gammopathy of Undetermined Significance

Definition

Monoclonal gammopathy of undetermined significance (MGUS) is defined by a monoclonal immunoglobulin in serum that amounts to 30 g/L or less, the presence of 10% or fewer plasma cells in the bone marrow, the absence of anemia and lytic bone lesions, and the absence of hypercalcemia and renal insufficiency related to the aberrant clonal proliferation of plasma cells. MGUS is the most common disorder among a group of diseases referred to as plasma cell dyscrasia. Because of the high prevalence in elderly patients (∼5%), MGUS is a very common finding in the doctor’s office. MGUS does not require treatment, but the need for monitoring is lifelong. This is due to the intrinsic propensity of MGUS cell clones to complete the malignant transformation process and, thus, undergo progression to multiple myeloma (MM). The progression from MGUS to MM, an invariably fatal neoplasm, occurs at a slow but remarkably steady rate of 1% per year.

Characteristics

Epidemiology

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