Medical Definition of Cyst, pilonidal
Cyst, pilonidal: An abscess that occurs in the cleft between the buttocks. Pilonidal cysts form frequently in adolescence after long trips that involve sitting, and they may be painful. Treatment frequently involves surgery if not responsive to heat applications and antibiotics.
Quick GuideRosacea, Acne, Shingles: Common Adult Skin Diseases
Subscribe to MedicineNet's Skin Care & Conditions Newsletter