[1] Singapore Gen Hosp, Dept Pathol, Singapore 169608, Singapore
[2] Chinese Univ Hong Kong, Prince Wales Hosp, Dept Anat & Cellular Pathol, Hong Kong, Hong Kong, Peoples R China
[3] Univ Nottingham, Nottingham City Hosp NHS Trust, Dept Histopathol, Nottingham NG7 2RD, England