According to NTD, Dr Kemer Ramirez of Bogota's Tunjuelito Hospital said that the doctor overseeing the woman noticed something 'abnormal in her abdomen' - and suspected gallstones.
An ultrasound showed nothing then radiography of her abdomen revealed a tumour in her abdominal cavity.
Dr Ramirez explained: "This happens because the foetus does not develop in the uterus because it has moved to another place.
"In this case, the abdominal part of the woman is not a viable (place) and this is what happened, a calcified fetus because the body is generating defence mechanisms and it is calcified until it stays there encapsulated."
The patient is thought to have been transferred to another hospital to have the lithopedion removed.
In 2009, a 92-year-old Chinese woman was found to have a 60-year-old 'stone baby' inside her.
The first reported case of lithopedion was Madame Colombe Chatri, a 68-year-old French woman.
An autopsy after her death in 1582 revealed she had been carrying a fully-developed stone baby in her abdominal cavity for 28 years.
- Daily Mail