Chronic lymphocytic leukemia with hyperleukocytosis. The hyperviscosity syndrome

A 47-year-old man with hyperleukocytic chronic lymphocytic leukemia progressively developed retinal hemorrhages, headache, diplopia, dysequilibrium, slurred speech, nystagmus, ataxic gait, and hearing loss as his leukocyte count rose to a maximum of 968,000/mm3. All of these symptoms and signs resolved promptly after leukapheresis. The authors reviewed records of 210 patients with chronic lymphocytic leukemia seen at our institution over a 12-year period, and found 16 patients with sustained hyperleukocytosis above 500,000/mm3, 3 of whom had features of the hyperviscosity syndrome. No laboratory values consistently predicted the occurrence or lack of occurrence of the hyperviscosity syndrome. The key to the management of hyperviscosity syndrome in the setting of hyperleukocytic chronic lymphocytic leukemia is to consider the diagnosis and to rapidly lower the lymphocyte count.