Myeloma: MGUS, Multiple Myeloma

Question 1

MGUS

• pathophysiology, types
• risk factors
• complications
• presentation
• diagnosis
• management

Answer 1

Asymptomatic premalignant plasma cell proliferative disorder in BM => production of M protein (has no AB function) => may progress to multiple myeloma, increased risk of fractures, VTE, infections

• Non IgM MGUS
• IgM MGUS

Genetic mutations - t(14:11), (14:6), TP53
More common in older males

Asymptomatic
Rash, paraesthsia, hypoesthesia

Labs - monoclonal proteins
BM biopsy - low plasma cells

Watch and wait

Question 2

Multiple myeloma

• pathophysiology
• presentation
• diagnosis

Answer 2

Neoplasm of plasma cells in BM => overproduction of M paraprotein (abnormal IgG, IgA or free light chains)

CRAB

• calcium elevated <= increased bone resorption
• renal disease <= AKI from accummulation of light chains, paraproteins in glomerulus
• anemia <= BM failure
• bone lysis (pathological fractures in axial skeleton, long bones) <= increased bone resorption

Skeletal survey - Xray, CT, MRI of spine
Genetic - FISH
Serum - monoclonal free chains, high Ca
Urine - Bence Jones protein
BM biopsy - high plasma cells

Chemo, immunomodulators, autologous/allogenic stem cells
Symptomatic - bisphosphonates, ABx, glucocorticoids

Question 3

Metastasis

Answer 3

Other bone marrow