Step 1: Distinguish a keloid from an ordinary scar - it is an overgrowth of collagen that spills past the wound edges and tends to come back after removal.
Step 2: The overgrowth is fuelled by raised levels of fibrogenic growth factors (notably TGF-beta) acting on fibroblasts, so the option stating that it contains growth factor is correct.
Step 3: Plain wide excision is a poor sole treatment because cutting a keloid out usually triggers recurrence, often with a larger lesion, so adjuncts like steroid injection or radiotherapy are added.
Step 4: Since a keloid characteristically grows beyond the original wound boundary, the claim that it stays within the wound is wrong, leaving growth factor content as the true statement.
\[\boxed{\text{It contains growth factor}}\]