1. Department of Anatomical Pathology, South African Institute for Medical Research
2. Department of Radiology, Chris Hani Baragwanath Hospital
3. Department of Anatomical Pathology, Chris Hani Baragwanath Hospital and the South African Institute for Medical Research
4. Department of Otorhino-laryngology, Johannesburg Teaching Hospitals (Dr. McIntosh) and the University of the Witwatersrand, Johannesburg, South Africa.