Plasma Cell Cancer

Question 1

Multiple myeloma is a plasma cell cancer that arises where?

Answer 1

In the bone marrow

Question 2

What are the 3 key ideas behind multiple myeloma that account for all its signs/symptoms?

Answer 2

• excess secretion of osteoclast activation factor
• excess Ig secretion
• proportionally high light chain production

Question 3

What are some signs/symptoms in multiple myeloma due to hi osteoclast activation factor?

Answer 3

• hi serum Ca
• lytic (punched out) lesions in the vertebre+skull
• hi risk for fracture

(OAF binds to RANK-R on osteoclast, incr. activity)

Question 4

What are some signs/symptoms in multiple myeloma due to excess Ig secretion?

Answer 4

• hi serum protein (M spike on a SPEP due to high levels of monoclonal Ab; mostly IgG and IgA)
• hi susceptibility to infection (less Ag diversity; #1 cause death in multiple myeloma)
• Rouleaux formation (RBC stack on each other due to Ig linking)

Question 5

What are some signs/symptoms in multiple myeloma due to proportionally hi light chain production?

Answer 5

• accumulates in tissues (primary amyloidosis; AL)
• excreted in urine (Bence Jones protein)
• accumulates in renal tubules (causes nephrotic syndrome, hi risk for renal failure)

Question 6

What acronym can be used to remember multiple myeloma signs?

Answer 6

CRAB

hi Calcium, Renal issues, Anemia, Bone lesions

Question 7

Differentiate between common signs and symptoms of multiple myeloma and adult T cell lymphoma.

Answer 7

both have hi Calcium and lytic bone lesions

T cell lymphoma: mostly Japan/Caribbbean/East Africa, RASH, caused by HTLV-1

Question 8

Differentiate between multiple myeloma and Waldenstrom’s macroglobinemia.

Answer 8

WM: also has M spike, but due to IgM.

IgM=pentameric, so get hyperviscosity; also no lytic bone lesions

Question 9

How is MGUS different from multiple myeloma?

Answer 9

MGUS: M spike, but no other signs of multiple myeloma (though pts do have higher risk of developing MM)

Question 10

Langerhans histiocytosis is a proliferation of what type of cell?

Answer 10

specialized dendritic cells of monocyte lineage

found in high concentrations in the skin

Question 11

What are two common markers seen in cells of Langerhans histiocytosis?

Answer 11

S100 and CD1a

Question 12

What characteristic cell is seen on electron microscopy in Langerhans histiocytosis?

Answer 12

tennis racket cells; aka Birbeck granules