HANOI  - A man left unable to walk by a tumour on his right leg that weighs more than the rest of his body went under the knife in Vietnam on Thursday to have the growth removed, hospital officials said. Nguyen Duy Hai’s massive 90 kilogramme (198 pounds) tumour is to be cut away by a team of doctors in a risky ten hour procedure that has only a 50 percent success rate, the France-Vietnam (FV) hospital in Ho Chi Minh City said. Hai, 31, who suffers from a rare genetic disorder, has been living with the tumour since he was four years old, FV hospital’s statement read.