A Colombian woman suffering from stomach pain was found to have a 40-year-old fetus inside her.
The 82-year-old, from Bogota, had what is known as 'lithopedion', or stone baby, when the unborn child develops outside the womb.
The woman was originally thought to be suffering from a stomach bug, NTD TV reports.
But an scans revealed lithopedion, where the fetus becomes calcified.There are fewer than 300 cases reported in medical literature.
The woman will now will undergo surgery to have the fetus - mostly comprised of dead tissue - removed.
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.