Plasma Cell

Question 1

Which Ig is most likely to cause hyper viscosity?

Answer 1

IgM

Question 2

What % of dogs with MM develop high serum viscosity?

Answer 2

20%

Question 3

What % of dogs with MM develop Bence Jones proteinuria?

Answer 3

25-40%

Question 4

Can Bence Jones proteinuria be detected on a dipstick?

Answer 4

Nope

Question 5

What IHC markers identify plasma cells?

Answer 5

MUM1

CD138?

Question 6

ORR and MST of multiple myeloma to daily melphalan and pred?

Answer 6

ORR 92% (43% CR, 49% PR)
MST 540d (1.5yr)

Question 7

What are three negative prognostic indicators for MM?

Answer 7

hyperCa, osteolytic lesions, Bence-Jones proteinuria

Question 8

How did pulse dose melphalan compare to daily regarding tolerability and MST? (Fernandez 2018)

Answer 8

Both well-tolerated with MST of 930d (2.5yr)

pulse = 7 mg/m2/day for 5 days every 21 days

Question 9

In recent study comparing two protocols for melphalan treatment, what were two negative prognostic factors? (Fernandez 2018)

Answer 9

renal disease and high neutrophil: lymphocyte ratio (used cut-off of 4.28)

Question 10

Was PCR clonality useful to diagnose canine cutaneous plasmacytoma? (Takenosu 2018)

Answer 10

No, may be due to somatic hypermutation of variable region.

Question 11

What is the recommended treatment and expected survival for canine cutaneous plasmacytosis (in absence of MM)? (Boostrom 2017)

Answer 11

Response to alkylating agents (melphalan, Lomustine) + pred; survival times similar to those in MM with alkylating agents (MST 542d)

Question 12

What was response rate and survival for MM with rabacfosadine single agent? (Thamm 2014)

Answer 12

82% response (9/11), MST 172d (5.7mo)

one dog with melphalan-refractory dz had CR for >1047d

Question 13

How does melphalan compare to twice weekly Cytoxan to manage feline MRD? (Cannon and Borgatti 2015)

Answer 13

Similar MST (252 for melphalan, 394 for CTX)
ORR was 71% for melphalan and 83% for CTX

Question 14

How was melphalan vs. CTX tolerated in cats with MRD? (Cannon and Borgatti 2015)

Answer 14

Hematologic toxicity common with melphalan, CTX was well tolerated (mild toxicity).

Question 15

What factor was close to statistical significance as a negative prognostic factor for cats with MRD? (Cannon and Borgatti 2015)

Answer 15

hypoalbuminemia

Question 16

What is Waldenstrom’s disease?

Answer 16

macroglobuinemia - if the M component is IgM

Question 17

What is tx of choice for macroglobulinemia?

Answer 17

chlorambucil; study of 9 dogs - 77% achieved remission; MST 11 mo

Question 18

In which three locations are extramedullary plasmacytomas most likely to be benign?

Answer 18

cutaneous, oral, colorectal

upper GI more aggressive and more likely to met to local LN

Question 19

What is the relationship between SOPs and MM?

Answer 19

The majority of SOPs eventually progress to MM, but may take months/years