Estela Melendez had something called a ‘Lithopedion.’ This phenomenon is so rare that there are only 300 recorded cases in the history of medicine.Doctors first thought it was a tumourAfter the 92-year-old woman had a fall, she went to the hospital where doctors informed her about the strange discovery. The elderly woman was shocked and flabbergasted to find out that she had a fifty-year-old foetus in her abdomen.About 50 years ago, the Melendez went to the doctor because she had a big bump in her stomach. At the time, physicians didn’t realise that she had an ‘unborn’ child in her belly—instead, they initially suspected something else. ‘The doctor said I had a tumour,’ she told BBC News. 50 years later, the elderly woman now understands that she lived with a foetus for more than half of her life.Rare phenomenon Melendez had no idea that she had been pregnant, and her unborn foetus was living inside of her for over 40 years. It was only when she went to the hospital after her fall that doctors took an X-ray and finally solved the problem.Calcified foetuses, also known as Lithopedions, are extremely rare and there are only 300 recorded cases in the history of medicine. The only thing that might be rarer is cases of mothers not giving birth to their first child until they are over the age of 70.