A recent editorial in the American Heart Journal calls attention to the frequently overlooked increased blood viscosity which complicates macroglobulinemia and occasionally myeloma. In the current issue of the Archives of Internal Medicine, Kopp and co-workers2 highlight another hemodynamic complication, that of increased blood volume and consequent dilutional anemia which can occur in these conditions. Both complications have important clinical implications in diagnosis and therapy.
First reported by Reismann3 in The Journal 37 years ago, and subsequently confirmed by other observers as an occasional finding in myeloma, elevated blood viscosity was subsequently found to be more consistently present in macroglobulinemia. A number of observers have delineated a syndrome entirely attributable to this hyperviscosity. The syndrome is characterized by bleeding from mucous membranes, retinal hemorrhages, headache, vertigo, nystagmus, ataxia, deafness, paresthesias, impaired gait, and occasionally cardiac involvement with congestive heart failure. Singly, or in various combinations, these symptoms occurred