MULTIPLE MYELOMA Flashcards
What is the primary diagnostic criterion for myeloma?
A) Serum M component >3 g/dL
B) Bone marrow plasmacytosis >10%
C) Detection of Bence Jones proteins in urine
D) Presence of extramedullary plasmacytomas
Answer: B) Bone marrow plasmacytosis >10%
Rationale: Diagnosis of myeloma requires bone marrow plasmacytosis (>10%), a serum and/or urine M component, and at least one myeloma-defining event.
Which of the following features distinguishes MGUS from myeloma?
A) Bone marrow plasmacytosis <10%
B) Presence of serum M protein
C) Risk of progression to active disease
D) Abnormal kappa/lambda free light chain ratio
Answer: A) Bone marrow plasmacytosis <10%
Rationale: MGUS is characterized by marrow plasmacytosis <10% and lack of myeloma-defining events, distinguishing it from myeloma.
What percentage of patients with MGUS progress to myeloma annually?
A) 0.5%
B) 1%
C) 5%
D) 10%
Answer: B) 1%
Rationale: Approximately 1% of MGUS patients per year progress to myeloma.
What is the defining feature of solitary bone plasmacytoma?
A) Extramedullary tumor involvement
B) Bone marrow plasmacytosis >10%
C) A single lytic bone lesion without marrow plasmacytosis
D) Presence of Bence Jones protein in the urine
Answer: C) A single lytic bone lesion without marrow plasmacytosis
Rationale: Solitary bone plasmacytoma is characterized by a single lytic lesion without significant marrow plasmacytosis.
Which subtype of myeloma is most associated with hyperviscosity?
A) IgA myeloma
B) IgG myeloma
C) IgM paraproteins
D) Light chain myeloma
Answer: C) IgM paraproteins
Rationale: IgM paraproteins are more likely to cause hyperviscosity compared to IgA and IgG myelomas.
Which diagnostic tool is most useful for assessing the extent of bone marrow infiltration in myeloma?
A) X-ray
B) Serum protein electrophoresis
C) Magnetic resonance imaging (MRI)
D) Chest CT scan
Answer: C) Magnetic resonance imaging (MRI)
Rationale: MRI is sensitive for documenting bone marrow infiltration and complications like cord or root compression.
What is the significance of a serum β2-microglobulin level in myeloma?
A) It differentiates MGUS from smoldering myeloma.
B) It is a marker of disease activity and prognosis.
C) It confirms the presence of an M component.
D) It predicts the likelihood of extramedullary disease.
Answer: B) It is a marker of disease activity and prognosis.
Rationale: Serum β2-microglobulin is a key prognostic marker in myeloma.
Why is a 24-hour urine collection necessary in myeloma workup?
A) To measure total immunoglobulin levels
B) To detect Bence Jones protein excretion
C) To assess renal function
D) To quantify serum free light chains
Answer: B) To detect Bence Jones protein excretion
Rationale: A 24-hour urine specimen is needed to quantify Bence Jones protein (light chain) excretion.
What is the primary diagnostic criterion for Monoclonal Gammopathy of Undetermined Significance (MGUS)?
A) Serum monoclonal protein (non-IgM type) <30 g/L
B) Clonal bone marrow plasma cells ≥10%
C) Absence of myeloma-defining events or amyloidosis
D) Both A and C
Correct Answer: D
Rationale: MGUS is diagnosed by the presence of serum monoclonal protein <30 g/L (A) and the absence of myeloma-defining events or amyloidosis (C). Clonal bone marrow plasma cells must be <10% (not B), distinguishing it from other conditions.
Which of the following criteria is essential to diagnose Smoldering Multiple Myeloma (SMM)?
A) Serum monoclonal protein >30 g/L or urinary monoclonal protein >500 mg per 24 hours
B) Presence of myeloma-defining events
C) Clonal bone marrow plasma cells ≥60%
D) A single lytic lesion detected on imaging
Correct Answer: A
Rationale: SMM requires serum monoclonal protein >30 g/L or urinary monoclonal protein >500 mg per 24 hours, without myeloma-defining events (B). Clonal bone marrow plasma cells in SMM are 10–60%, making C incorrect. A single lytic lesion (D) is a myeloma-defining event, which excludes SMM.
Which finding is NOT considered a myeloma-defining event in symptomatic multiple myeloma?
A) Hypercalcemia: Serum calcium >0.25 mmol/L above the upper limit of normal
B) Anemia: Hemoglobin value <100 g/L
C) Lytic bone lesions on imaging
D) Serum M protein <10 g/L
Correct Answer: D
Rationale: A, B, and C are all myeloma-defining events as they indicate end-organ damage due to plasma cell proliferation. Serum M protein levels are not part of the myeloma-defining criteria but are used for categorization and risk assessment.
What is a distinguishing feature of solitary bone plasmacytoma?
A) Presence of clonal plasma cells in bone marrow ≥10%
B) An isolated lytic lesion with no other evidence of systemic disease
C) Serum M protein >30 g/L
D) Evidence of myeloma-related end-organ damage
Correct Answer: B
Rationale: Solitary bone plasmacytoma is characterized by a single lytic bone lesion (B) without systemic involvement such as clonal bone marrow plasma cells ≥10% (A) or myeloma-related end-organ damage (D). Serum M protein may be absent or present in small amounts.
Which condition is associated with the presence of Castleman’s disease and elevated vascular endothelial growth factor (VEGF) levels?
A) Smoldering Multiple Myeloma
B) POEMS Syndrome
C) Solitary Plasmacytoma
D) Nonsecretory Myeloma
Correct Answer: B
Rationale: POEMS Syndrome includes polyneuropathy, organomegaly, endocrine abnormalities, monoclonal plasma cell disorder, and skin changes. Elevated VEGF levels and Castleman’s disease are key features that differentiate it from other plasma cell disorders.
What are the two primary goals of therapy in patients with symptomatic multiple myeloma?
A) Systemic therapy to control myeloma and management of anemia
B) Systemic therapy to control myeloma and supportive care for symptoms and complications
C) Reduction of monoclonal protein levels and prevention of fractures
D) Maintenance of renal function and improvement of bone lesions
Correct Answer: B
Rationale: The two primary goals of therapy are systemic treatment to control the disease and supportive care to manage symptoms, complications, and therapy side effects. Other options address specific issues related to myeloma but are not comprehensive goals.
Which combination therapy is preferred as an induction regimen for transplant-eligible multiple myeloma patients?
A) Lenalidomide, bortezomib, and dexamethasone
B) Thalidomide and dexamethasone
C) Melphalan and prednisone
D) Cyclophosphamide and dexamethasone
Correct Answer: A
Rationale: The combination of lenalidomide, bortezomib (a proteasome inhibitor), and dexamethasone achieves close to a 100% response rate and >30% complete response (CR) rate, making it one of the preferred induction regimens for transplant-eligible patients.
What is the mechanism of action of daratumumab, which is used in multiple myeloma therapy?
A) Proteasome inhibition
B) Anti-CD38 antibody targeting plasma cells
C) Immunomodulation through T-cell activation
D) Alkylation of DNA to prevent cell replication
Correct Answer: B
Rationale: Daratumumab is an anti-CD38 antibody that targets CD38, a surface protein highly expressed on plasma cells, providing deeper responses in combination therapies. Proteasome inhibition (A) is achieved by bortezomib and carfilzomib, and immunomodulation (C) is the role of agents like lenalidomide and thalidomide.
