Medical researchers have made a surprising anatomical discovery, finding what appears to be a mysterious group of salivary glands hidden inside a human's head, which scientists have somehow overlooked for centuries now.

This "unknown entity" was identified by chance by doctors in the Netherlands, who were examining patients with prostate cancer with an advanced type of scan called PSMA PET / CT. And when combined with an injection of radioactive glucose, the diagnostic tool highlights tumors in the body.