Sebaceous cysts are noncancerous and non-dangerous outgrowths of the skin. They mostly appeared on the face, neck, or torso. They are slow growing and are not dangerous but if they left unchecked they may become uncomfortable. These cysts arise due to blockage of sebaceous glands and look like hard outgrowth on the skin. They rarely vanish by medication only surgical excision is helpful for permanent removal of the cyst.