Even Dr. Pimple Popper can be surprised by what slips out of her incisions. In a new Instagram video, Sandra Lee, MD, uprooter of countless deposits of puffy keratin goo and gelatinous skin slime, opens what looked like an abscess above a patients lip. With one quick pinch between her finger and thumb, a small calcified mass plops out onto her thumbnail.

Its like, you know, a little river rock, remarks the TLC host. Dr. Pimple Popper then shows the stone's release again in slow motion.

The "stone" was probably sialolithiasis , which are like kidney stones for your mouth. Also called salivary duct stones, they are crystalized components of spit, which occur in 1.2 percent of the population. Rarely do the stones grow larger than a centimeter. Sialothiasis most often develops in the jaw, sometimes causing pain while eating, and can lead to pain and infection. However, some stones show up in the lip .

View this post on Instagram A teeny tiny river rock in the upper lip! #drpimplepopper A post shared by Sandra Lee, MD, FAAD, FAACS (@drpimplepopper) on Sep 9, 2019 at 9:32pm PDT

Dentists semi-frequently encounter salivary duct stones, but they can be a surprise to general practitioners, ER doctors and dermatologists, like Lee.

Raj Waghmare, an emergency physician, who blogs at ERTales.com , wrote of removing a painful one from a patients mouth .

I carried it around with me the entire shift, Waghmare recounts. I showed it to my ER colleagues, the internists, and even a couple of surgeons. Id tell them the story. Never, one of them said. Not in twenty-eight years. Never seen that before."