The unusual growth was attributed to a brain tumor. Within that tumor were the fully-formed teeth.
It is conjectured the baby's case is a historical first.
Surgery was performed to remove the tumor, and the four-month-old is now recovering.
It all began when a routine health check indicated the baby boy's head was growing at a much rapid rate than normal for his size.
A report in the New England Journal of Medicine documented how an MRI scan was ordered, and later revealed the tumor in the baby's pituitary gland. Even more astounding was that the tumor contained fully formed teeth similar in size to those typically found in the lower jaw.
Tests on the removed tumor showed it to be a slow-growing mass known as adamantinomatous craniopharyngioma. They are sometimes full of yellow fluid of high viscosity and even contain cholesterol crystals. The National Cancer Institute has indicated that this type of tumor has been diagnosed in chldren aged 5 to 14, but are rare in those younger than age 2.
Doctors say the tumor likely arose from the Rathke's pouch, which is the pituitary gland's embryonic precursor. Moreover, they believe the tumor grew from the same cells involved in the creation of teeth, which explains their unexpected appearance in the brain.
According to University of Maryland Medical Center neurosurgeon Dr. Narlin Beaty, "It's not every day you see teeth in any type of tumor in the brain. In a craniopharyngioma, it's unheard of."
While these tumors are known to have some calcium deposits, Beaty emphasized the uniqueness of the case: "...when we pulled out a full tooth...I think that's something slightly different."
Since the tumor's removal, the boy has had a shunt fitted to drain spinal and brain fluid from his cranial region. Unfortunately, the tumor undermined the normal connections of the brain that would allow the secretion of certain key hormones. For this reason, the boy has been prescribed thyroid and adrenal hormone-replacement treatments, that will likely continue for the rest of his life. Regular MRI scans are also undertaken to ensure the tumor does not return.