Removal of the brain was an Egyptian mummification procedure that became popular around 3,500 years ago and remained in use in later periods.
Researchers said it is only the second time that such a tool has been reported within a mummy's skull, 'LiveScience' reported.
The object, discovered in 2008 through a series of CT scans, was located between the left parietal bone and the back of the skull, which had been filled with resin.
Researchers inserted an endoscope into the mummy to get a closer look and ultimately detach it from resin to which it was stuck.
"We cut it with a clamp through the endoscope and then removed it from the skull. It almost definitely would have been used in exacerbation [brain removal] of the mummy," said lead researcher Dr Mislav Cavka, of the University Hospital Dubrava in Zagreb Croatia.
They found themselves peering at an object more than 3 inches long that would have been used for liquefying and removing the brain.
The tool would have been inserted through a hole punched into the ethmoid bone near the nose of the mummy.
"Some parts [of the brain] would be wrapped around this stick and pulled out, and the other parts would be liquefied," Cavka said.
The Egyptian mummy could then be put on its abdomen and the liquid drained through the nose hole.
"It is an error that [the] embalmers left this stick in the skull," said Cavka, adding the tool may have broken apart during the procedure.
This finding has provided researchers with a very rare artifact. They point the only other brain-removal stick found inside a mummy's skull dates back 2,200 years.
"Probably in museums in Egypt there are many other evidences, but they were not found inside the skull," making it tricky to identify such artifacts as brain-removal tools, said Cavka.
The mummy of the woman who died around the age of 40 is currently in the Archaeological Museum in Zagreb Croatia, where it was brought without a coffin.
The study was published in the journal RSNA RadioGraphics.
