MIAMI -- A 14-year-old Haitian girl was undergoing a groundbreaking operation Wednesday at Holtz Children's Hospital to remove a 16-pound growth from her face.

The operation, which began around 8:30 a.m., is the first of many Marlie Casseus must undergo.

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"Marlie is not suffering from a tumor, OK? This is a genetic disorder called fibrous dysplasia," said Dr. Jesus Gomez, of the University of Miami Miller School of Medicine.

The teen suffers from a rare form of Polyostotic Fibrous Dysplasia, a nonhereditary, genetic disease that causes bone to become "like a big a bowl of jelly with some bone inside," according to Gomez.

Gomez said about 150,000 people worldwide are diagnosed with the disease, but only 3 percent suffer such an extreme condition. He added this growth was the largest he had ever seen and that every bone in her body was involved with the disease. Her liver and spleen were already altered because of it.

Casseus came to the United States in September for emergency treatment. The growth had become so large that it was difficult for her to breathe. Doctors at that time inserted a breathing tube into her throat.

One month after her case was made public, the $95,000 needed for Casseus' surgery was donated to the International Kids Fund.

"We have had donations from places as far away as Iceland, places like Latvia, like Germany," said Josephine Mora, of the International Kids Fund.

Casseus' mother, Maleine Antoine, described her child's desperation.

"She would touch my face to ask me, 'Why?' and asking, 'When are they going to take this off my face?'" Antoine said.

Casseus' mother said she is grateful to the doctors who have donated their time.

The reshaping of Casseus' face will last between 12 and 14 hours. Surgeons hope to save Casseus' sight.

"It is growing, and it's starting to grow into her eye socket, which is dangerous to her, because if it grows any further it can cause her to go blind," said Dr. Wendy Lee, of the Bascom Palmer Eye Institute.

"It's possible until she finishes puberty that this thing is going to keep growing, and hopefully we can delay this process," said Dr. Kami Parsa, of the Bascom Palmer Eye Institute.

Casseus' physical disorder has caused her a lot of emotional pain.

"She was treated like an animal. It's very sad to say that, but the people in her village in Haiti, if she was walking down the sidewalk, they would turn to the other side to avoid her," Gomez said.

Trying to reconstruct Casseus' face and jaw will take several years and numerous surgeries. Her mother is grateful to the twin sisters who brought Casseus to Miami for help and hope.

Surgeons said Casseus is not going to look perfect after this surgery. She will be in intensive care for about a week. Blood loss and infection are main concerns.

Doctors will update the public on Casseus' condition on Friday.