Sebaceous cysts, by definition, are not malignant and have zero malignant potential. However, they can become infected if bacteria gets trapped within this sack of dead skin.
Normally, sebaceous cysts are asymptomatic. If the cyst partially ruptures, and dead skin ends up in the surrounding tissue, a foreign body reaction can result. This looks like a red, lump of skin and can be very tender. As mentioned earlier, if bacteria gets into this closed space or sac, an abscess can result that may be very tender and often requires drainage.
Removing sebaceous cysts is quite simple. We numb up the skin in the area, nick the top of the skin with a small blade and remove the entire cyst sac outside of the skin.