[1] Univ Leeds, Leeds Inst Canc & Pathol, Leeds, W Yorkshire, England
[2] Univ Turin, Dept Oncol, Oral Med & Oral Oncol Unit, Turin, Italy
[3] Univ Turin, Dept Med Sci, Pathol Unit, Turin, Italy
[4] Natl Guard Hosp, Dept Pathol & Lab Med, Riyadh, Saudi Arabia
[5] Queen Victoria Hosp, Dept Histopathol, E Grinstead, W Sussex, England
[6] St James Univ Hosp, Dept Histopathol, Leeds LS2 9LU, W Yorkshire, England
[7] Univ Leeds, Leeds Dent Inst, Leeds, W Yorkshire, England