What you're looking at here is an x-ray of a 4-month-old baby's skull that was taken by doctors at a Maryland hospital.

The infant's skull had been growing abnormally fast, and it was later diagnosed as craniopharyngioma, an extremely rare type of brain tumor most often found in children between the ages of 5 and 14.

What's especially creepy is that the tumor also had several fully-formed human teeth inside:
"It's not every day you see teeth in any type of tumor in the brain. In a craniopharyngioma, it's unheard of," Beaty said.

Craniopharyngiomas commonly contain calcium deposits, "but when we pulled out a full tooth...I think that's something slightly different,"

Teeth have been found in people's brains before, but only in tumors known as teratomas, which are unique among tumors because they contain all three of the tissue types found in an early-stage human embryo, Beaty said. In contrast, craniopharyngiomas have only one layer of tissue.

The boy's case provides more evidence that craniopharyngiomas do indeed develop from the cells that make teeth, Beaty said.
Doctors say that the infant is doing just fine, although the tumor destroyed some of his brain's hormone-regulation function and he'll need lifelong hormone treatments. Speedy recovery little guy!

[Livescience]