This "invisible" blackhead is one of Dr. Pimple Popper's most interesting pops. Upon first look, you can't even see the pimple, so Dr. Lee pointed out the small bump under the skin on the patient's top lip that she was removing. To the average viewer, it's almost invisible, but Dr. Lee was able to detect and extract it.

Dr. Lee started by making a small incision on the bump, and then widened the incision to remove the pimple. But things got really interesting when Dr. Lee began squeezing the mass, as typically, the insides of pimples are somewhat wet, comprised of old skin cells. But in this case, a small, solid, kidney bean-shaped mass jumped out of the skin in one swift pop. 

Dr. Lee described the mass as "a little river rock," and told her patient she thinks the mass was a calcified cyst, but she wasn't positive. After removing the mass, the patient was ready to get stitched up and sent on her way, but the interesting pimple makes it one of Dr. Pimple Popper's best cases yet.