Keloid scars are characterized by excessive collagen deposition that grows beyond the original wound boundaries, leading to raised, firm, and often irregularly shaped scars. Unlike hypertrophic scars, keloids do not regress over time and can cause functional and cosmetic impairment. This uncontrolled scar expansion is due to an abnormal wound healing response, with persistent fibroblast proliferation and collagen synthesis. Recognizing that keloids extend beyond the initial injury is crucial for surgical planning and counseling patients about recurrence risks. Complete excision must be combined with adjunctive therapies to prevent regrowth.

Reference: Plastic Surgery: Volume 3 - Craniofacial, Geoffrey C. Gurtner, 4th Edition.