Weird spikes poking through a teen's eyelid turned out to be a wayward tooth

The symptoms: The teen developed swelling on his left upper eyelid that persisted for a few months but was painless. However, he later noticed two sharp, white projections poking out from the skin above his eye.

About a month after these projections appeared, he went to a hospital.

What happened next: Doctors examined the teen's eyelid, noting that the spikes had a "fairly smooth surface and were hard on palpation," said Dr. Meghana Tanwar , a medical consultant at the Aravind Eye Hospital in India who co-authored a report of the case . The texture and color of the projections suggested they might be teeth, she told Live Science in an email.

Initially, the doctors thought the points also might have been related to a teratoma, a rare type of tumor that can include different types of tissue, including bone and tooth tissue. They also wondered if the projections might be a foreign body in the eyelid. They conducted a CT scan to take a closer look.

The diagnosis: The scan revealed that the projections were indeed part of a tooth.

"The structure of a lone tooth in the superior orbit was quite obvious," Tanwar said. "Superior orbit" refers to the upper eye socket, and the tooth had poked out in the small space between the boy's eyelid and eyebrow.

Teeth that develop and erupt in abnormal locations are known as ectopic teeth. This umbrella term includes teeth that are in the mouth but erupt outside their typical positions; for instance, in about 2% to 6% of people , their first permanent molars grow "out of place" in the expected line-up of teeth.

In this case, though, the patient had an ectopic tooth that appeared completely outside the dental arch, which is far rarer .