what is a sebaceous cyst
A sebaceous cyst is a small, closed sac under the skin that contains oily or cheesy material. The cyst forms a smooth, firm bump or lump, most often on the face, scalp, neck, or middle of the body.A sebaceous cyst may occur if you have a blocked sweat gland or hair follicle. sebaceous cyst is a small, closed sac under the skin that contains oily or cheesy material. The cyst forms a smooth, firm bump or lump, most often on the face, scalp, neck, or middle of the body.