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A 14-year-old boy from Cuba who underwent surgery in Florida to remove a 4.5-kg (10-lb) tumour from his face has died.

Emanuel Zayas suffered from a rare condition called polyostotic fibrous dysplasia, which causes certain bones to become soft. The condition caused a benign tumour to develop on Zayas' face three years ago.

Zayas’ parents tried in vain to find a local specialist who could help their son. His family was finally granted a temporary humanitarian visa to travel to Jackson Memorial Hospital in Miami, Fla. to meet a team of facial surgeons.

With the tumour growing heavier and pressing on Zayas’ trachea, the medical team decided to proceed with surgery earlier this month to remove the tumour and rebuild Zayas' nose.

Though Zayas appeared to be recovering last week, his condition worsened over the weekend and he developed kidney and lung failure.

“Our condolences and prayers for Emanuel’s family and the loss of a very brave young man,” Dr. Robert E. Marx, the chief of oral and maxillofacial surgery at the University of Miami Health System, said in a statement.

“Another angel has arrived in Heaven.”

Marx told NBC Miami: “Apparently, the physiologic stress of the surgery was too much for his compromised anatomy to overcome.”

He added that his team’s hopes of allowing Zayas a better quality of life “have not been realized.”

Dr. Marx says Zayas’ family has donated their son’s body to medical research so that scientists can try to learn more about the rare disease.