Clonal proliferation of malignant plasma cells
Excessive production of monoclonal immunoglobulins or immunoglobulin fragments (kappa/lambda light chains)
History / PE:
Anemia, hypercalcemia, and bone pain Plasmacytosis of the bone marrow
Prone to infection
Diagnosis:
> 10% plasma cells in bone marrow
M protein in serum/urine (Bence-Jones proteins)
Elevated IgG or IgA
Lytic bone lesions
Bone marrow biopsy
Treatment:
Chemotherapy
Autologous stem cell transplant
Complications:
Renal failure (from obstruction of distal and collecting tubules)
Pneumonic:
Tetrad of common presenting symptoms ("CRAB")
C alcium ( hypercalcemia )
R enal impairment
A nemia
B ones (bone pain, lytic lesions, fractures)
Notes:
Elevated monoclonal (M) proteins in the serum/urine (also seen in MGUS, CLL, lymphoma, Waldenstroms macroglobulinemia, and amyloidosis )
Myeloma cells tend to become resistant to drugs by a MDR gene mechanism
Patients are at an increased risk of developing infections because they have less FUNCTIONAL antibodies
