1. Department of Neuropathology, Institute of Pathology; Ruprecht-Karls-University Heidelberg; Heidelberg Germany
2. Clinical Institute of Pathology; Medical University of Vienna; Vienna Austria
3. Clinical Cooperation Unit Neuropathology; German Cancer Research Center (DKFZ); Heidelberg Germany
4. Department of Neurosurgery; St. Ivan Rilski Hospital; Sofia Bulgaria
5. Department of Neuropathology; St. Ivan Rilski Hospital; Sofia Bulgaria
6. Department of Surgery; Medical University of Vienna; Vienna Austria
7. Department of Immunology, Institute of Microbiology; Bulgarian Academy of Sciences; Sofia Bulgaria
8. Department of Obstetrics and Gynecology; Medical University of Vienna; Vienna Austria
9. Department of Neurosurgery; Klinikum Idar-Oberstein; Idar-Oberstein Germany