You are asked to make a diagnosis in a 60-year-old man who presents with a 2-month history of bilateral blurring of his vision. He also notes weakness, fatigue, recurrent headaches, recurrent epistaxis, paresthesias in his feet, and a persistent rash on his legs. Your examination reveals a corrected vision of 10/20 in both eyes, an abnormal fundus (pictured), generalized adenopathy, splenomegaly, and a vascular rash on his lower extremities (pictured). He has diminished sensation to pain and temperature in his feet and lower legs. What is your diagnosis, what test(s) would you order to confirm your suspicions, and what treatment do you recommend?
DIAGNOSIS: Hyperviscocity syndrome secondary to Waldenstrom's macroglobulinemia (WM). WM is due to unfettered proliferation of monoclonal IgM-producing lymphoplasmacytoid cells (CD138 +, CD20 +). Unlike IgG and IgA, 80% of IgM (a pentamere) stays intravascularly, and, in sufficient concentrations, can cause a hyperviscocity syndrome (HVS).
As in this patient, HVS can cause visual impairment with fundiscopic changes of retinal vein dilatation and tortuosity and retinal hemorrhages; cutaneous bleeding due to platelet dysfunction may also occur (see photos above). Neurologic symptoms are common, and can include an altered state of consciousness (including coma), paresis, and chronic inflammatory demyelinating polyneuropathy. Nonspecific symptoms such as fatigue, malaise and weight loss are common. Unlike myeloma, patients with WM have generalized adenopathy and hepatosplenomegaly.
Immediate plasmaphoresis is indicated for patients with HVS. The malignancy is treated with rituximab sometimes in combination with corticosteroids or chemotherapy. Allogeneic stem cell transplants may be successful in patients with recalcitrant disease.