Size of lesion commensurate with original injury. Scarring is limited to boundaries of original injury. May regress spontaneously in 12-18 months. Tends to improve with surgical correction. Histopathology of Keloid Scars Haphazard deposition of collagen fibers in the dermis.
Extracellular matrix is mucinous with eosinophils, mast cells, plasma cells, and lymphocytes.
Collagen appears as thick hyalinized bands in nodular formation. Nodules are a dense mass of fibroblasts and collagen encircled by small vessels. Histopathology of Keloid Scars Electron microscopy shows partial to full occlusion of the vessels secondary to excessive endothelial proliferation. Histopathology of Hypertrophic Scars Increased collagen bundles, in parallel relation to the skin surface. Increase numbers of fibroblasts.