A cyst is a sac of tissue containing fluid or air that can form in many areas of the body. Cysts often do not need to be removed unless they are causing pain or other problems. There are several ...

Medically reviewed by Susan Bard, MD Key Takeaways A pilonidal cyst is a painful lump located at the base of the spine at the top of the buttocks.Symptoms can include a painful lump, discharge, and ...