Skin cysts are not cancerous. A skin cyst is a skin lesion that has a structure with a cystic cavity containing fluid or other components from the skin or mesenchymal tissue. Most skin cysts appear as pimples, nodules, or swellings that protrude from the surface of the skin. Skin cysts are not considered tumor tissue and are generally not cancerous. Most skin cysts can gradually subside with aggressive and effective treatment, such as surgical excision, electrocautery, liquid nitrogen freezing, and high-frequency electrosurgery, but skin cysts may recur.