Spinal dermoid and epidermoid cysts are benign growths in the spine. Although they are not cancerous and will not spread, they may compress important structures like the spinal cord or spinal nerves, and they may eventually rupture. Therefore, when they are found in the spine, these cysts are surgically removed.

Both dermoid and epidermoid cysts contain skin material. Both are lined with a layer of skin that naturally sheds dead cells. But instead of shedding to the outside of the body, the shed skin cells accumulate inside the cyst. In this way, the cysts gradually expand.

Dermoid and epidermoid cysts differ in their other contents. While epidermoid cysts are lined with simple skin cells, and contain only the products of skin cells, like the protein keratin, dermoid cysts contain skin cells, their products, many other skin components like hair follicles, hair, or sweat glands, but also other material like tooth material, oil, or blood.