1. Department of Neurosurgery, Azienda Ospedaliera Universitaria di Sassari, Via Enrico De Nicola, Sassari, Italy,
2. Medical Oncology Unit, University Hospital of Parma, Parma, Italy.
3. Department of Anatomy and Pathological Histology, Azienda Ospedaliera Universitaria (AOU) di Sassari, Italy.