What is an abnormal growth of scar tissue that is thick and irregular called?

The correct answer is keloid, which refers to an abnormal growth of scar tissue that results from an overproduction of collagen during the healing process. Keloids are characterized by their thick, raised appearance and their tendency to extend beyond the boundaries of the original injury. This condition often arises after surgery, trauma, or even minor skin injuries. Unlike normal scars, which can fade and flatten over time, keloids often persist and may require medical treatments to manage their appearance.

In the context of the other choices, a fissure is a narrow slit or crack in the skin, often painful, but it does not refer to abnormal scar development. A plaque is usually a term associated with raised lesions or patches on the skin, often seen in conditions like psoriasis, and does not indicate scar tissue growth. An ulcer describes a sore on the skin or a mucous membrane that fails to heal properly, typically due to underlying conditions, rather than a growth of fibrous tissue. Understanding these distinctions helps clarify why keloid is the only option that describes an abnormal growth of scar tissue specifically.