Plasma Cell Disorders

Question 1

What is the most common primary malignancy of bone?

Answer 1

Multiple myeloma

Question 2

What interleukin may be high in multiple myeloma?

Answer 2

IL-6 (important grwoth factor for plasma cells)

Question 3

What is multiple myeloma?

Answer 3

Malignant proliferation of plasma cells in bone marrow

Question 4

What can plasma cells produce in relation to bone?

Answer 4

Osteoclast activating factor

Question 5

How does multiple myeloma present?

Answer 5

• Bone pain w. hypercalcemia

- Increased risk of fracture

Question 6

What will be seen on X-ray in multiple myeloma?

Answer 6

• Lytic ‘punched-out’ lesions

- Increased risk of fracture

Question 7

What does multiple myeloma activate?

Answer 7

• Neoplastic plasma cells activate RANK receptor on osteoclasts

Question 8

What would be seen on serum protein electrophoresis in those with multiple myeloma?

Answer 8

• ‘M spike’
• Sharp spike in gamma region due to increase in immunoglobulins
• Monoclonal immunoglobulin (usually IgG, may be IgA)

Question 9

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

Answer 9

Infection (monoclonal antibody lacks antigenic diversity)

Question 10

What is seen on blood smear in multiple myeloma?

Answer 10

• Rouleaux formation (RBCs stacking on top of each other)

- Due to increased protein decreasing charge between RBCs

Question 11

What is primary AL amyloidosis?

Answer 11

• 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)

Question 12

What is MGUS - Monoclonal Gammopathy of Undetermined Significance?

Answer 12

Increased serum protein with M spike w/o other symptoms associated with multiple myeloma

Question 13

What percentage of 70 year-olds have MGUS?

Answer 13

5%

- 1% of patients each year will go on to develop multiple myeloma

Question 14

What is Waldenstrom Macroglobulinemia?

Answer 14

B-cell lymphoma w. monoclonal IgM production

Question 15

What are the clinical features of Waldenstrom Macroglobulinemia?

Answer 15

• 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

Question 16

How is Waldenstrom Macroglobulinemia treated?

Answer 16

• Acute complications treated with plasmapheresis (removes IgM from the serum)

Question 17

Where are Langerhan cells found?

Answer 17

Skin

Question 18

What is Langerhans cell histiocytosis?

Answer 18

• Neoplastic proliferation of Langerhans cells

Question 19

What is seen on EM in Langerhans cell histiocytosis?

Answer 19

• Characteristic Birbeck (tennis racket) granules

Question 20

What does immunohistochemistry show with Langerhans cell histiocytosis?

Answer 20

Cells are CD1a+ and S100+

Question 21

What is Letterer-Siwe disease?

Answer 21

Malignant proliferation of Langerhans cells

Question 22

What is the classic presentation of Letterer-Siwe disease?

Answer 22

• Skin rash and cystic skeletal defects in an infant (<2 yrs)
• Multiple organs may be involved
• Rapidly fatal

Question 23

What is eosinophilic granuloma?

Answer 23

Benign proliferation of Langerhans cells in bone

Question 24

How does eosinophilic granuloma classically present?

Answer 24

Pathologic fracture in an adolescent; skin is not involved

Question 25

What does a biopsy show in eosinophilic granuloma?

Answer 25

Lanerhans cells with mixed inflammatory cells, including eosinophils

Question 26

What is Hand-Schuller-Christian disease and how does it present?

Answer 26

• Malignant proliferation of Langerhans cells

- Classic presentation is scalp rash, lytic skull defects, diabetes insipidus, and exopthalmus in a child