Also called an epidermal cyst , a sebaceous cyst results from an accumulation of sebum. The sebum excretory ducts are blocked, so the sebum can no longer reach the surface of the skin and is no longer able to fulfill its role as a skin protector. This excess sebum will manifest itself by the appearance of a ball under the skin : the sebaceous cyst.
Be careful not to confuse a sebaceous cyst with a lipoma . Unlike a lipoma, a cyst is not made of fat .
Mainly found on the face , neck , trunk but also on the scalp (we speak of scalp magnifying glass or trichilemmal cyst), the sebaceous cyst takes the form of a swelling or subcutaneous nodule of a size generally less than 2 cm. The presence of a black point that overcomes the cyst is possible.