Multiple Myeloma | Anatomy2Medicine
Multiple Myeloma Types

Multiple Myeloma

    • Plasma cell disorders
  • neoplastic proliferations of well-differentiated immunoglobulin-producing cells.
    • These disorders include
  • multiple myeloma
      • Waldenström macroglobulinemia
      • benign monoclonal gammopathy
  • primary amyloidosis and heavy-chain (Franklin) disease.
  • most frequent in persons older than 40–50 years of age.
  • Multiple myeloma (plasma cell myeloma/plasmacytoma)
  • is a malignant plasma cell tumor
    • usually affect older persons
  • typically involves bone
  • associated with prominent serum and urinary protein abnormalities.
  • Clinical characteristics of multiple myeloma
  • Bone lesions and protein abnormalities
  • The neoplastic cell is an end-stage derivative of B lymphocytes that is clearly identifiable as a plasma cell.
  • The neoplastic cells can easily be identified by bone marrow biopsy or aspiration smears.
        • The tumor cells produce lytic lesions in bone, especially in the skull and axial skeleton.
        • Appearance of  bone lesions
          • lucent on radiographic examination, with characteristic sharp borders, and are referred to as punched-out lesions
  • manifest radiographically as diffuse demineralization of bone (osteopenia).(MCQ)
    • caused by an osteoclast-activating factor secreted by the neoplastic plasma cells. .(MCQ)
  • associated with severe bone pain and spontaneous fractures.
  • Paraproteinemia
        • Myeloma arises from proliferation of a single clone of malignant antibody-producing cells.
        • tumor cells produce massive quantities of identical immunoglobulin molecules demonstrable electrophoretically as a narrow serum band or, after densitometric scanning, as a sharp spike referred to as an M protein. .(MCQ)
        • M protein in multiple myeloma is most often an IgG or IgA immunoglobulin of either kappa or lambda light-chain specificity. (MCQ)
        • Synthesis of normal immunoglobulins is often impaired.
        • The marked serum immunoglobulin increase is often initially detected by laboratory screening as increased total protein with an increase in serum globulin  .(MCQ)
        • The urine often contains significant quantities of free immunoglobulin light chains, either kappa or lambda, which are referred to as Bence Jones protein. .(MCQ)
        • As a consequence of hyperglobulinemia, the red cells tend to congregate together in a manner reminiscent of a stack of poker chips (rouleaux formation). .(MCQ)
      • There is also a marked increase in the ESR. .(MCQ)
  • Anemia
        • due to neoplastic encroachment on myeloid precursor cells;
      • Possible leukopenia and thrombocytopenia
      • Increased susceptibility to infection
        • Due to  impaired production of normal immunoglobulins
  • Hypercalcemia
        • secondary to bone destruction
  • in contrast to the increased serum alkaline phosphatase that accompanies most other instances of hypercalcemia, the serum alkaline phosphatase in multiple myeloma is not increased. .(MCQ)
      • Renal insufficiency with azotemia due to myeloma kidney (myeloma nephrosis).
        • The renal lesion is characterized by
          • prominent tubular casts of Bence Jones protein
  • numerous multinucleated macrophage-derived giant cells
          • metastatic calcification
          • interstitial infiltration of malignant plasma cells.
  • Amyloidosis of the primary amyloidosis type .(MCQ)
    • Waldenström macroglobulinemia
  • a manifestation of lymphoplasmacytic lymphoma
  • a B-cell neoplasm of lymphoid cells of an intermediate stage between B lymphocytes plasma cells referred to as plasmacytoid lymphocytes
    • neoplastic cells produce a monoclonal IgM protein (lymphoplasmacytic lymphomas can also occur without protein production). .(MCQ)
    • Defining characteristics
      • Serum IgM immunoglobulin of either kappa or lambda specificity occurring as an M protein .(MCQ)
  • Plasmacytoid lymphocytes infiltrating the blood, bone marrow, lymph nodes, and spleen
      • Bence Jones proteinuria in about 10% of cases
      • Absence of bone lesions.(MCQ)
    • Clinical features
      • Most frequently seen in men older than 50 years of age
      • Slowly progressive course, often marked by generalized lymphadenopathy and mild anemia
    • Complications
      • Hyperviscosity syndrome
        • results from marked increase in serum IgM .(MCQ)
        • retinal vascular dilation, sometimes with hemorrhage, confusion,
        • central nervous system changes are seen
        • emergency plasmapheresis is required to prevent blindness.
      • Abnormal bleeding,
  • due to vascular and platelet dysfunction secondary to the serum protein abnormality
    • Benign monoclonal gammopathy (monoclonal gammopathy of undetermined significance, or MGUS)
  • occurs in 5%–10% of otherwise healthy older persons.
      • A monoclonal M protein spike of less than 2 g/100 mL.(MCQ)
      • minimal or no Bence Jones proteinuria
      • less than 5% plasma cells in the bone marrow .(MCQ)
      • no decrease in concentration of normal immunoglobulins is characteristic.
  • MGUS is most often without clinical consequence.