An Almost Fatal Case of the Hypereosinophilic Syndrome: A Dilemma Between Vasculitis or Clonal Disorder

Hypereosinophilic syndrome (HES) is a rare and potentially life-threatening disorder. While many conditions can cause eosinophilia, it can also be provoked by rarer diseases such as vasculitis or myeloproliferative disorders. Here we present an almost fatal presentation of HES characterized with both vasculitis and clonal features. Treatment with combined chemo-immunotherapy allowed reversal of most of the complications. There is still much uncertainty in the diagnosis and management of HES, and research should be done to improve knowledge on pathophysiology and cytogenetics of this disease in order to improve treatment and prevent life-threatening complications.