An American surgeon, known for removing big tumors, will operate on a Vietnamese man Thursday to remove a one metre long, 90 kilogramme tumor in his right leg.

Dr. McKay McKinnon of Chicago, together with Vietnamese doctors, will perform the operation on Nguyen Duy Hai, 31, at the Ho Chi Minh City Tumour Hospital.

Hai's tumor is the largest ever recorded in Vietnam, according to Vu Van Thach, head of examination department of Hanoi Tumour Hospital. The tumor started growing since Hai was born and his right leg became bigger than the left leg by the time he was four years old.

Doctors later learned that the man from Central Highlands province of Lam Dong is suffering from Neurofibromatosis type I (NF-1), a human genetic disorder.

At age 17, the leg from the knee was amputated, but the tumour kept growing. Because the tumour was so big, he had to sleep in sitting position and had to rely on his mother for all his needs because he could barely move. Has has been admitted to the Ho Chi Minh City Tumour Hospital since July last year.

The surgery was made possible through cash donations after Hai appealed to the public for funds to cover the medical cost of removing the tumour.

Dr. McKinnon previously operated on a Romanian woman to remove an 80-kilo tumour on her back and thighs. He and Romanian surgeons successfully removed the tumour on Lucica Bunghez, 46, of Transylvania in an 8-hour operation in 2004.
Like Hai, Bungez, suffered from NF, which caused the disfiguring tumours to form on nerves throughout the body.

In 2000, Dr. McKinnon also successfully removed a 91-kilogramme tumour caused by the same disorder from Lori Hoogewind, of Wyoming, Michigan.