Plasma Cell Disorders (Dyscrasias)

Question 1

What is the most common plasma cell dyscrasia?

Answer 1

MGUS

Question 2

What is multiple myeloma?

Answer 2

• plasma cell cancer
• rearrangements of the Ig heavy chain (IgG/IgA)
• excessive monoclonal Ig production
• tumor cells produce IL-6, aiding tumor survival
• CD138, CD56, and syndecan-1 (commone plasma cell markers)

Question 3

What is the common presentation of multiple myeloma?

Answer 3

• older adults (median 65-70)
• painful lytic bone lesions with a “punched-out” appearance
• humoral immune dysfunctions
• hypercalcemia

-renal failure

Question 4

What are potential findings/complications of multiple myeloma? (there are several)

Answer 4

• pathologic fractures
• elevated serum protein with M spike
• increased risk of infection, most common COD (due to mass amounts of monoclonal Ab)
• AL amyloidosis (increased Ig light chains)
• renal failure (second most common COD) with Bence Jones protien (Ig light chain found in urine)

-Rouleaux formation of RBCs

Question 5

What is the course/prognosis of multiple myeloma?

Answer 5

somewhat aggressive course

variable prognosis depending on progression (median survival 4-7 years)

no cure

Question 6

What is solitary myeloma?

Answer 6

mild version of multiple myeloma in which there is only one bony lesion (hence single vs. multiple)

Question 7

What is MGUS?

Answer 7

monoclonal gammopathy of uncertain significance

-asymptomatic elevation of M proteins

Question 8

What is the common presentation of MGUS?

Answer 8

• elderly
• asymptomatic (by definition missing symptoms of MM)

Question 9

Compare multiple myeloma, smoldering myeloma, and MGUS.

Answer 9

MM:

• symptomatic
• bone marrow bioposy >30% plasma cells
• >3g/dL serum M protein
• Bence-Jones protein

Smoldering myeloma (transition from MGUS to MM; 75%):

• asymptomatic
• bone marrow bioposy 10-30% plasma cells
• >3g/dL serum M protein

MGUS (1% progress to MM):

• asymptomatic
• <3g/dL serum M protein
• no Bence-Jones protein