A pilonidal dimple is a small pit or sinus in the sacral area just at the top of the crease between the buttocks. The pilonidal dimple may also be a deep tract, rather than a shallow depression, leading to a sinus that may contain hair. During adolescence the pilonidal dimple or tract may become infected forming a cyst-like structure called a pilonidal cyst. These pilonidal cysts may require surgical drainage or total excision to prevent reinfection.
Debra G. Wechter, MD, FACS, General Surgery Practice Specializing in Breast Cancer, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.