Plasma Cell Disorders Flashcards
What is the most common primary malignancy of bone?
Multiple myeloma
What interleukin may be high in multiple myeloma?
IL-6 (important grwoth factor for plasma cells)
What is multiple myeloma?
Malignant proliferation of plasma cells in bone marrow
What can plasma cells produce in relation to bone?
Osteoclast activating factor
How does multiple myeloma present?
- Bone pain w. hypercalcemia
- Increased risk of fracture
What will be seen on X-ray in multiple myeloma?
- Lytic ‘punched-out’ lesions
- Increased risk of fracture
What does multiple myeloma activate?
- Neoplastic plasma cells activate RANK receptor on osteoclasts
What would be seen on serum protein electrophoresis in those with multiple myeloma?
- ‘M spike’
- Sharp spike in gamma region due to increase in immunoglobulins
- Monoclonal immunoglobulin (usually IgG, may be IgA)
What is the most common cause of death in multiple myeloma?
Infection (monoclonal antibody lacks antigenic diversity)
What is seen on blood smear in multiple myeloma?
- Rouleaux formation (RBCs stacking on top of each other)
- Due to increased protein decreasing charge between RBCs
What is primary AL amyloidosis?
- Result of multiple myeloma
- Free light chain circulates in serum and deposits in tissues
- Free light chain is excreted in urine as Bence-Jones proteins
- Deposition in kidney tubules leads to risk for renal failure (myeloma kidney)
What is MGUS - Monoclonal Gammopathy of Undetermined Significance?
Increased serum protein with M spike w/o other symptoms associated with multiple myeloma
What percentage of 70 year-olds have MGUS?
5%
- 1% of patients each year will go on to develop multiple myeloma
What is Waldenstrom Macroglobulinemia?
B-cell lymphoma w. monoclonal IgM production
What are the clinical features of Waldenstrom Macroglobulinemia?
- Generalised LAD; lytic bone lesions absent
- Increased serum protein w. M spike (compromised of IgM)
- Visual and neurological defecits (e.g. retinal hemorrhage or stroke)
- Bleeding
How is Waldenstrom Macroglobulinemia treated?
- Acute complications treated with plasmapheresis (removes IgM from the serum)
Where are Langerhan cells found?
Skin
What is Langerhans cell histiocytosis?
- Neoplastic proliferation of Langerhans cells
What is seen on EM in Langerhans cell histiocytosis?
- Characteristic Birbeck (tennis racket) granules
What does immunohistochemistry show with Langerhans cell histiocytosis?
Cells are CD1a+ and S100+
What is Letterer-Siwe disease?
Malignant proliferation of Langerhans cells
What is the classic presentation of Letterer-Siwe disease?
- Skin rash and cystic skeletal defects in an infant (<2 yrs)
- Multiple organs may be involved
- Rapidly fatal
What is eosinophilic granuloma?
Benign proliferation of Langerhans cells in bone
How does eosinophilic granuloma classically present?
Pathologic fracture in an adolescent; skin is not involved
What does a biopsy show in eosinophilic granuloma?
Lanerhans cells with mixed inflammatory cells, including eosinophils
What is Hand-Schuller-Christian disease and how does it present?
- Malignant proliferation of Langerhans cells
- Classic presentation is scalp rash, lytic skull defects, diabetes insipidus, and exopthalmus in a child