Case Presentation: 80 year-old-male with past medical history of hypertension, coronary artery disease, chronic systolic heart failure, diabetes mellitus type 2, chronic kidney disease stage 2 presented with acute onset of constant vertigo for 1 day. Patient had a history of intermittent moderate vertigo for 20 years, controlled on meclizine. However, at this presentation, patient’s vertigo was severe and constant, associated with vomiting, and did not improve with meclizine. Upon initial evaluation, CT head showed a left cerebello-pontine angle 1.3 cm mass suggestive of a meningioma or schwannoma. Outpatient records indicated this mass was stable for at least 3 years. Patient’s worsening vertigo was initially attributed to this mass and treatment with meclizine or benzodiazepines did not improve his symptoms. Laboratory data was remarkable for hemoglobin of 9.0 gm/dLand creatinine of 1.62 mg/dL. Total protein was 10.0 gm/dL and albumin was 3.4 g/dL, giving an elevated paraprotein gap of 6.4 g/dL. Further work-up of the elevated paraprotein-gap revealed an M-spike of 1.6 g/dL, IgM kappa band identification on immunofixation, and an elevated viscosity level of 6.5. This prompted a bone marrow biopsy, which was consistent with Waldenström Macroglobulinemia. Patient was started on plasmapharesis, with a decrease of his viscosity level to 2.3 and resolution of his vertigo
Discussion: Waldenström Macroglobulinemia (WM) is a low-grade B-cell clonal disorder characterized by lymphoplasmacytic lymphoma in the bone marrow and an IgM monoclonal gammopathy in the blood. It is a rare disorder with an incidence of 3 per million people per year, and a median age of diagnosis at 70 years. Patients with WM can present with various symptoms which can be related to either bone marrow involvement (B symptoms, anemia, lymphadenopathy, hepatosplenomegaly) or to the effects of the IgM para-protein (blurry vision, headaches, cardiac ischemia, peripheral neuropathy, renal insufficiency, diarrhea). Diagnosis requires IgM monoclonal gammopathy, a bone marrow with at least 10% infiltration by small lymphocytes with lymphoplasmacytic features or lymphoplasmacytic lymphoma, and an immunophenotype typical for WM. First-line therapies for WM include single-agent alkylators or nucleoside analogs. Hyperviscosity syndrome can be treated with plasmapheresis. A single volume of plasmapheresis can decrease the serum viscosity by up to 60%.
Our patient presented with acute on chronic vertigo and the initial etiology was falsely determined to be a stable cerebello-pontine mass. However, a work-up of patient’s elevated paraprotein gap revealed an alternative diagnosis of WM associated with hyperviscosity. This was more consistent with the patient’s acute presentation.
Conclusions: An acute change in neurological status, along with an elevated paraprotein gap should prompt concern for hyperviscosity syndrome. This case highlights the harmful consequences of anchoring to a diagnosis, and the importance of recognizing the various presentations of WM.