August 14th, 2020
Multiple myeloma (MM) consists of a neoplastic proliferation of plasma cells that accumulate in the bone marrow and produce a monoclonal immunoglobulin (IgG, IgM, IgA, or rarely, IgE or IgD) or light chain protein (kappa or lambda).
MM accounts for 1% of all cancers and ~10% of all hematologic malignancies. It is twice more common in blacks than whites, with a slight male predominance. Median survival is 5 to 7 years.
The median age of presentation is 70 years of age; 15% of patients are less than 65 years old. Persons of African descent tend to present at a younger age.
Multiple myeloma is asymptomatic initially. In such individuals, it is usually identified incidentally, e.g. via laboratory studies showing hypercalcemia, anemia, or proteinuria.
Bone disease is present in 80-90% of patients. Pain is due to bony infiltration and pathologic fractures.
Features of hyperviscosity syndrome
Features of hyperviscosity syndrome range from mild headache, dizziness or dyspnea, to severe manifestations such as altered mentation, transient ischemic attacks, retinal hemorrhages, and deep venous thrombosis.
Hyperviscosity syndrome occurs due to high concentrations of serum monoclonal proteins.
Features of hypercalcemia
Hypercalcemia can present with numerous symptoms, including:
○ Neurologic symptoms (e.g. fatigue and altered mental status);
○ Gastrointestinal symptoms (e.g. anorexia, nausea, vomiting, and constipation); and,
○ Renal symptoms (e.g. polyuria due to nephrogenic diabetes insipidus)