Ultrastructural characteristics of keloid fibroblasts.

Myofibroblasts abound in granulation tissue, where they play an important role in the healing process. We evaluated the characteristics of fibroblasts in ten patients with keloids, a disorder of skin wound repair. Keloid lesions uniformly exhibited numerous fibroblasts with prominent Golgi complexes and abundant rough endoplasmic reticulum. Although rare fibroblasts exhibited a convoluted nucleus and tangled microfilaments, none could be characterized as myofibroblast, as defined by cytoplasmic myofilaments and cell to cell junctions. We conclude that fibroblast density and activity are increased in keloids, but true myofibroblasts are not a component of these lesions.