STICKING TO A SUSPICION – A CASE OF HYPERVISCOSITY SYNDROME
Abstract Number: 726
A 50 year old woman with hypertension and sciatica presented with a 2 month history of intermittent abdominal, leg and back pain, and a 14-lb weight loss. Her initial exam was unremarkable. Laboratory data was significant for elevated serum calcium to 11mg/dL and total protein to 11.4g/dL, a newly elevated Cr of 1.15mg/dL and new anemia with Hgb 7.2g/dL. CT imaging of the abdomen and pelvis and skeletal X rays showed multiple lytic lesions of the vertebral, iliac and femur bones. Additional lab work showed ESR >140, normal PTH, abnormal gamma globulin spikes on SPEP and UPEP, and markedly elevated free lambda M protein on UIFE and SIFE, with a serum IgM at 8950mg/dL. Bone marrow biopsy revealed almost complete replacement with lymphoid cells, plasmacytoid lymphocytes and plasma cells suggestive of a lymphoplasmacytic lymphoma, presumed Waldenstrom’s macroglobulinemia (WM). Given the patient’s marked serum IgM burden, somatic complaints, and new intermittent headache, hyperviscosity syndrome (HVS) was suspected. Pending the results of the serum viscosity, a fundoscopic exam was performed and showed cotton wool hemorrhages. The patient underwent urgent plasmapheresis, and her symptoms subsided. Days later, her serum viscosity finally resulted at 4.2CP (normal 1.4-1.8CP) and decreased to 1.6CP with continued plasmapheresis. Ultimately, FISH analysis of the bone marrow showed absence of the MYD88 mutation and t(11;14) with over 90% of cells positive for t(14;16), suggestive of an aggressive IgM myeloma rather than WM. Despite early initiation of chemotherapy, the patient had recurrent HVS, progressive pancytopenia and died within the year.
Discussion: We describe a rare case of multiple myeloma with IgM paraprotein complicated by HVS. IgM myeloma comprises <1% of all multiple myeloma cases and is typically distinguished from WM by the presence of lytic bone lesions and specific cytogenetic abnormalities. Our case also highlights the importance of early recognition and treatment of HVS, which can be the presenting or complicating manifestation of several hematologic disorders. Symptoms are usually uncommon at serum viscosity levels below 4CP and can include skin and mucosal bleeding, blurred vision, headache, ataxia, and neuropathy. Severe HVS may cause confusion, stroke and coma. HVS is a medical emergency and requires immediate plasmapheresis to prevent further complications. However, serum viscosity is not uncommonly a ‘send out’ test and results can take days. A prompt fundoscopic exam may be life saving; hemorrhages and a “sausage link” appearance of retinal veins are classic findings.
Conclusions: Our case highlights the potential pitfall of relying on lab values alone for diagnosing hyperviscosity syndrome. Keeping a high index of suspicion in those with an IgM monoclonal gammopathy is critical, especially when the disease burden is high. Early recognition and treatment can drastically affect outcomes.
To cite this abstract:
STICKING TO A SUSPICION – A CASE OF HYPERVISCOSITY SYNDROME.
Abstract published at Hospital Medicine 2017, May 1-4, 2017; Las Vegas, Nev..
Journal of Hospital Medicine Volume 12 Suppl 2.
July 8th 2020.