Ach Fung1, Ksh Chok2, Awi Lo3, C M Lo2. 1. Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pok Fu Lam Road, Hong Kong, China. 2. Department of Surgery, The University of Hong Kong, 102 Pok Fu Lam Road, Hong Kong, China. 3. Department of Pathology, Queen Mary Hospital The University of Hong Kong, 102 Pok Fu Lam Road, Hong Kong, China.