An Unusual Neurological Presentation in a Patient with Primary Hypereosinophilic Syndrome.

Hypereosinophilic syndromes are characterized by an increased number of blood eosinophils (usually more than 1.5 x 10(9)) infiltrating tissues and causing organ damage through over-production of pro-inflammatory cytokines with heteroge-neous clinical presentation. Here we present a case of a 47 years old male, with an unremarkable previous medical history, with a sudden onset of subungual hemor-rhage and low back pain. Admitted for right arm weakness and vomiting, was raised the suspicion of acute cerebrovascular syndrome, but a brain CT scan with angiogram and perfusion sequences did not show any signs of early ischaemic lesions; conversely, lab tests revealed an increased peripheral eosinophil blood count. Clinical conditions rapidly worsened and a brain MRI showed multiple sub-acute ischaemic lesions compatible with vasculitis while EEG was in favor of wide-spread cortical distress. Diagnosis of the hypereosinophilic syndrome was made through peripheral blood smear and osteo-medullar biopsy, which showed a rich prevalence of eosinophils. The molecular biology testing showed FIP1L1-PDGRA gene mutation. Despite the prompt therapy beginning with intravenous corticoste-roids and tyrosine-kinase inhibitors with normalization of cell blood count in a few days, the patient remained in minimal consciousness. When facing unusual symp-toms onset (low back pain with weakness in one limb) and a highly impaired WBC not consistent with other courses (such as infections, vasculitis, allergies, and other diseases involving the immune system) clinicians should take into account the pos-sibility of a hematological disorder and treat it as soon as possible to avoid a poor prognosis