During surgery to remove a 16-year-old girl’s appendix, surgeons discovered a surprise guest— a tumor with a brain, hair and neurons that could transmit electric impulses like a normal brain.
The nearly 4-inch-wide tumor also had a thin plate of skull bone covering the 1.18-inch brain, which included a tiny version of a cerebellum and a mass that resembled a brain stem, New Scientist reported.
While it’s not uncommon for brain cells to be found in ovarian teratomas— tumors that contain foreign tissue including hair, teeth, cartilage, fat and muscle— this patient’s situation was unusual.
“Neural elements similar to that of the central nervous system are frequently reported in ovarian teratomas, but structures resembling the adult brain are rare,” Angelique Riepsamen at the University of New South Wales in Australia, told New Scientist.
It’s not known what causes ovarian teratomas, but one theory is that immature cells turn rogue and produce different body parts, New Scientist reported.
Fortunately, the unnamed patient didn’t suffer symptoms, but neurological symptoms can occur when the immune system labels the brain cells in the ovary as foreign and attacks— while also attacking the cells in the woman’s real brain. Other cases have reported that women with the unusual tumors have developed personality changes, paranoid thoughts, confusion, agitation, seizures or memory loss.
Doctors removed the tumor and the patient is recovering.