Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:
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- Normal cells transform into myeloma cells at the hematopoietic stem cell level.
- Pathologic derangements:
- Tumor cells within marrow lead to bone destruction and cytopenia.
- Immunodeficiency develops secondary to suppression of normal immune functions.
- Myeloma proteins lead to hyperviscosity and amyloidosis.
- Multifactorial renal failure
- Plasma cell secretions activate osteoclasts, leading to:
- Bone lysis, pathologic fractures, and neurologic impairment
- Hypercalcemia (exacerbated by impaired renal function)
- Anemia due to marrow infiltration and renal insufficiency
- Immunocompromised due to:
- Decrease in the number of normal immunoglobulins
- Qualitative and quantitative defects in T- and B-cell subsets
- Decreased cell-mediated immunity
- Hyperviscosity secondary to protein accumulation:
- Leads to high-output congestive heart failure
- Myeloma light chains accumulate in the renal epithelial cells and destroy the entire nephron.
- Clinical signs such as anemia, renal insufficiency, or lytic bone lesions
- Pathologic fractures
- Renal failure
- Recurrent infection
- Spinal cord compression (10% of all multiple myeloma [MM] patients)
- Incidence: 4/100,000 population:
- 1% of all cancers
- 15% of all hematopoietic malignancies
- 10,000 deaths/yr
- Mean age at diagnosis is 70 yr
- Slightly higher incidence in men and African Americans (reason unknown)
- Rarely seen in children.
- <2% in patients <40 yr of age