A 72-year-old man presents with progressive weakness, IgM monoclonal spike of 5.2 g/dL, bone marrow showing >10% lymphoplasmacytic cells, and MYD88 L265P mutation. He develops symptomatic hyperviscosity. What is the FIRST step in management?
- A Urgent plasmapheresis to reduce IgM rapidly ✓
- B Initiate ibrutinib therapy targeting BTK
- C Start rituximab monotherapy immediately
- D Administer high-dose dexamethasone to reduce IgM production
Correct answer: A. Urgent plasmapheresis to reduce IgM rapidly
Explanation
In Waldenström macroglobulinemia with symptomatic hyperviscosity (headache, visual changes, neurological symptoms), the immediate priority is plasmapheresis (plasma exchange), which rapidly reduces circulating IgM and relieves symptoms within hours. Ibrutinib (BTK inhibitor), rituximab, and chemotherapy are effective for disease control but take weeks to reduce IgM — they are initiated after plasmapheresis stabilizes the patient. Rituximab can transiently increase IgM (flare phenomenon) and should not be given during a hyperviscosity crisis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.