I assume you've been able to ask your doctor by now, but if it helps, here's a description of that kind of cyst.
An epidermoid, or epidermal, cyst is a small, movable, dome-shaped, smooth-surfaced lump under the skin. It can vary in size from less than a quarter of an inch to more than 2 inches. Epidermoid cysts can occur on almost any skin surface. It forms when surface skin cells move deeper into the skin and multiply. These cells form the wall of the cyst and secrete a soft, yellowish substance called keratin, which fills the cyst. If the wall of the cyst is ruptured, the keratin is discharged into the surrounding skin, which causes irritation and inflammation.
The cyst may remain small for years, or it may continue to get larger. These cysts common in adults. Cysts are not cancerous.
Your doc should be able to advise you regarding whether the white skin and hairs that you noticed are related to the cyst.