A 62-year-old man with known IgM monoclonal gammopathy reports blurred vision and recurrent epistaxis. Funduscopy shows dilated, segmented retinal veins with a sausage-like appearance. Serum viscosity is measured at 6.0 cP relative to water. What is the most appropriate immediate next step in management?

• A Start rituximab-based chemotherapy and reassess viscosity after two cycles
• B Begin aspirin 150 mg daily for hyperviscosity prophylaxis
• C Perform urgent therapeutic plasmapheresis ✓
• D Administer intravenous immunoglobulin to modulate antibody production

Explanation

Symptomatic hyperviscosity syndrome in Waldenstrom macroglobulinemia, with visual blurring, mucosal bleeding, and the classic sausage-link retinal veins, is a medical emergency treated first with plasmapheresis, which rapidly removes the circulating IgM. Chemotherapy such as rituximab combinations lowers IgM over weeks to months but acts too slowly to relieve symptoms. Aspirin does not correct hyperviscosity, and IVIG would add protein and worsen viscosity.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.