Vancouver IM LMR

Here are the didactic slides from today’s noon report on a VERY interesting and rare case of IgM multiple myeloma (<1% of multiple myeloma) presenting with hyperviscosity syndrome and acquired vWD.

I think a good takeaway from this case is to raise alarm bells when you see someone coming in with a strange constellation of symptoms on the background of a known history of IgM paraproteinemia – could this be a complication of those excess bulky immunoglobulins?

Key points:

1. Recognize the complications of IgM paraprotein (forms pentamers so leads to unique consequences) eg hyperviscosity, type I cryoglobulinemia, coagulopathy including acquired vWD, cold agglutinin disease
2. Differential diagnosis of IgM paraproteinemia includes IgM MGUS, Waldenstrom’s macroglobulinemia (new terminology: LPL = lymphoplasmacytic lymphoma), IgM multiple myeloma (<1% of MM cases), AL amyloidosis >> DLBCL, CLL
3. For those interested, IgM multiple myeloma and Waldenstrom’s macroglobulinemia are essentially indistinguishable clinically and this is a situation where we have to rely on the pathology, cytogenetics, etc. to help us understand what these abnormal cells are (see links for more details).