1. Department of Neurosurgery, University Hospital Policlinico-Vittorio Emanuele, Catania, Italy
2. Interdisciplinary Research Centre on Diagnosis and Treatment of Brain Tumors, University of Catania, Catania, Italy
3. Department of Radiodiagnostic and Oncological Radiotherapy, University Hospital Policlinico-Vittorio Emanuele, Catania, Italy
4. Institute of Neurosurgery, Catholic University, Rome, Italy
5. Department of Anatomic Pathology, University Hospital Policlinico-Vittorio Emanuele, Catania, Italy