A pilonidal cyst
, also called a pilonidal
sinus, is a small mass located under the skin primarily found in the natal cleft between the buttocks, along the coccyx
. These kinds of cysts mostly contain hair and skin, and tend to get infected on repeated occasions. Although they are completely benign
, when inflamed these cysts can cause intense pain. A pilonidal cyst can be surgically removed if inflamed, painful, or too large, yet ablation cannot guarantee the cyst will not resurface.