The immunohistochemical profile of the tumor was evaluated on 4 μ thick, formalin-fixed, deparaffinized sections using a DAKO Autostainer (Carpinteria, CA, USA) based on the avidin-biotin-peroxidase complex with antibodies ki-67 (dilution 1:320, DakoCytomation Corp, Carpinteria, CA), synaptophysin (dilution 1:600, DakoCytomation) and glial fibrillary acid protein [GFAP] (dilution 1:10, DakoCytomation). Here, GFAP is linked to neoplasm.