Pilonidal sinus—also called a pilonidal cyst—is a skin infection that occurs in or around the crease of your buttocks. This condition happens when hair, skin cells, and dirt clog a hair follicle, ...

What Is a Dentigerous Cyst? A dentigerous cyst, also called a follicular cyst, is the second most common type of jaw (odontogenic) cyst. It's a fluid-filled sac that develops in your jawbone over a ...

Incomplete sealing of the urachus — a line of connectivity between a fetus and the umbilical cord — can cause a urachal cyst to develop. It can lead to abdominal pain and other symptoms and often ...