Raised scar tissue on the skin, also known as a keloid, may be cancerous if the area continues to grow, according to Healthline. Keloids tend to be benign, but uncontrolled growth of a keloid can be a sign of cancerous cells forming.
Keloids form when the scar tissue grows excessively as it forms to repair the skin, notes Healthline. Typically keloids grow on the upper chest and shoulders, but they can form anywhere on the body. Keloids form at the site of an injury and may take weeks or months to fully develop. They may grow larger than the original wound but should not be cause for concern unless they continue grow uncontrolled.