Leukocytosis can occur with cancers that affect ... Some people may experience hyperleukocytosis symptoms such as: Difficulty breathing Vision problems Fever Headache Confusion Hyperleukocytosis ...

Many of these symptoms reflect leukocytosis and can be lessened by initial cytoreduction with hydroxyurea, to a white blood cell count of 10,000 - 20,000/mcL before starting interferon-alpha.