- Keloids are defined as scars that grow beyond the area of the wound that provoked them.
- Hypertrophic scars are defined as raised, exuberant scars that remain localized to the wound area.
- The clinical and histologic distinction between the two is not always crisp.
- Keloids can sometimes become quite disfiguring when of large size. Their etiology is unknown. They are significantly more common in blacks.
- Broad, haphazardly arranged, brightly eosinophilic collagen bundles
- Increased fibroblasts interspersed among the collagen bundles
- Usually elevated above the skin surface, often with an atrophic overlying epidermis
- Hypertrophic scars:
- Dense collagen bundles oriented parallel to the epidermal surface
- Marked increase in fibroblasts in the area of the hypertrophic collagen
- The scar shows minimal to no elevation above the skin surface.