Answer:
(From McCarthy, p738)
Both keloids and hypertrophic scars are characterized by excessive collagen deposition; the collagen is organized into discrete nodules, frequently obliterating the rete pegs in the papillary dermis of these lesions. Whereas collagen in normal dermis is arranged in discrete fascicles, separated by considerable interstitial space, the collagen nodules in keloids and in hypertrophic scars appear avascular and unidirectional, and are aligned in a “highly stressed” configuration.