Plasma Cell Dyscrasias

Question 1

Most common plasma cell neoplasm

Answer 1

Multiple myeloma

Question 2

Diagnostic criteria for multiple myeloma.

Answer 2

1. Clonal plasma cells – bm, plasmacytoma
2. M protein – Serum and/or urine, intact immunoglobulin OR Bence Jones proteins
3. End organ damage – CRAB –> hypercalcemia, renal insufficiency, anemia, bone disease

Question 3

Why is it important to obtain BOTH electrophoresis on the serum and urine for diagnosis of myeloma?

Answer 3

99% of myelomas have an M protein and/or Bence Jones protein
60-70% have serum M protein and Bence Jones proteins
20% have only Bence Jones proteins

Question 4

What is the most common cause of death in multiple myeloma?

Answer 4

Bacterial infection d/t immunosuppression – production of normal Igs suppressed with M protein, leading to recurrent infections

Question 5

Localized growth of monoclonal plasma cells

May be seen in multiple myeloma or as a distinct entity

Answer 5

Plasmacytomas

Question 6

Most common location for extramedullary plasmacytoma

Answer 6

80% occur in the URT

Question 7

Lymphoma with plasmacytic differentiation (B cells and plasma cells are neoplastic)
B cell lymphoa with monoclonal IgM production

Answer 7

Lymphoplasmacytic lymphoma

Question 8

Waldenstrom’s macroglobulinemia

Answer 8

Visual/neurlogic impariemnt

Cryoglobulinemia – Raynaud’s, Bleeding

Question 9

< 3 g/dL serum M protein
< 10% clonal plasma cells in BM
No myeloma-related end organ damage

Answer 9

MGUS (monoclonal gammopathy of undetermined significance)

Question 10

What percentage of MGUS develops to malignant transformation over 10-20 years?

Answer 10

25%

Generally multiple myeloma&raquo_space;> Lymphoplasmacytic lymphoma/Waldenstrom’s macroglobulinemia > Primary amyloidosis