It punctured her pharynx, broke two teeth and poked through a vertebra at the top of her neck, said Marcelo Amaral, the plastic surgeon that operated on her for two hours.
Removing it was a delicate operation because of arteries in the area, he said.
Had it landed a bit further to the right or left she would be paralyzed or dead, the doctor said.
"You can say that she has come back from the dead," Amaral told Globo News television.
The woman is starting to take food and drink orally, but cannot yet speak.