Vancouver IM LMR

Thanks Lucia for this excellent session on plasma cell dyscrasias!

Please see the teaching slides for your reference

High yield takeaways

1. In diagnosing multiple myeloma, sensitivity increases with each added test: SPEP (82%) -> IFE (93%) -> FLC/UPEP (97%)
2. A minority of MM (3%) is non-secretory – therefore changes would be seen on bone marrow biopsy but not detectable in blood tests.
3. MGUS must be risk stratified, with high risk factors including non-IgG M protein, M protein concentration over 15 g/L and abnormal SFLC ratio. Low risk MGUS and high risk MGUS are followed with labs in 6 months, and then q2-3 years (low risk) or q1year (high risk). Intermediate/high risk MGUS requires baseline bone marrow biopsy.
4. Watch out for cord compression in multiple myeloma – have a low threshold to image (MRI preferentially), as back pain can be present for 4-6 weeks prior to onset of objective neurological deficits. Urgent management includes high dose steroids, and consultations to Orthopedics and Radiation Oncology.
5. Hyperviscosity syndrome can occur in MM (or Waldenstrom’s macroglobulinemia) as a consequence of high protein content in the blood. Investigate with serum viscosity, normally 1.8 but up to >4 in these patients. Treatment by plasmaphresis and fluid replacement (dilution)
6. Consider amyloidosis in patients with restrictive cardiomyopathy without CAD, nephrotic-range proteinuria without DM, hepatomegaly without scan defects, atypical CIDP (or bilateral carpal tunnel), atypical myeloma.