Plasma Cell Dyscrasias Flashcards
What is the appearance of plasma cells in histology?
“Clock-face” Chromatin, moderate amount of cytoplasm
How can you tell if there is a reactive or neoplastic condition?
- Monoclonal antibodies in the serum/urine
- Single light chain found in flow cytometry
- Aberrancy
What might you find if there is a B-cell neoplasia?
- M-protein (the dominant monoclonal antibody)
- Bence-Jones Proteins (free light chains in urine)
- Electrophoresis identification (limited diversity, single types being produced)
What is the diagnostic criteria for Multiple Myeloma?
- Clonal plasma cells
- M-protein (serum/urine) and/or Bence Jones (IgG)
- End organ damage (hypercalcemia/lytic lesions/etc)
What are the most common sites to find lytic bone lesions?
Vertebrae, Ribs, and Skull
– Commonly found with pathologic fractures
What is lab finding is most consistent with multiple myeloma?
Hypercalcemia, due to bone reabsorption from the lytic lesions.
Renal Insufficiency – Bence-Jones proteinuria/ Tubular fracture casts
What does later stage multiple myeloma lead to?
Anemia – due to the replicating plasma cells the RBC proliferation runs out of room
Immunosuppression – due to the plasma cells only secreting specific antibodies, not covering the spectrum as normal, leading to infection/death
What is a plasmacytoma and where is it commonly located?
Plasmacytoma is a localized growth of plasma cells OUTSIDE of the bone marrow.
– Upper Respiratory Tract (Tx w/ radiation)
If a patient is found to have monoclonal IgM in serum and in the urine with both B-cells and plasma cells neoplastic on histology, what is the most likely diagnosis?
Lymphoplasmacytic Lymphoma
- Overproduction of IgM (instead of IgG)
- Waldenstrom’s Macroglobulinemia
What are effects most common associated with Waldenstrom’s Macroglobulinemia?
- Occusion of small blood vessels from IgM clusters
- visual / neurologic impairment
- Raynaud phenomenon
What is the most common Monoclonal gammopathy found in older adults?
Monoclonal Gammopathy of Undetermined Significance (MGUS)
- Typically no symptoms, but M-protein present and increased clonal plasma cells (less than 10% in BM)
- No end organ damage
What is the risk associated with MGUS?
Precursor Syndrome to Multiple Myeloma
– Must be closely monitored for changes/increases to the M-protein
If you have bone marrow specimen and there is positive apple-green birefringence, what might you be worried the patient has? (Congo Red Stain)
Multiple Myeloma
(Amyloidosis secondary to MM)
or Chronic Inflammatory condition
