1. Department of Surgery, Beaumont Hospital , Beaumont Road, Dublin 9, D09 V2N0 , Ireland
2. Department of Surgery, Royal College of Surgeons in Ireland , 123 St Stephen's Green, Dublin 2, D02 YN77 , Ireland
3. Department of Histopathology, Beaumont Hospital , Beaumont Road, Dublin 9, D09 V2N0 , Ireland
4. School of Medicine, Royal College of Surgeons in Ireland , 123 St Stephen's Green, Dublin 2, D02 YN77