A Colombian woman suffering from stomach pain was found to have a 40-year-old foetus 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 scans revealed lithopedion, where the foetus becomes calcified.There are fewer than 300 cases reported in medical literature.
The woman will now will undergo surgery to have the foetus - mostly comprised of dead tissue - removed.