Elastofibroma. A pseudotumor of myofibroblasts.

The fine structure of the cell of origin in elastofibroma showed features of both fibroblasts and smooth muscle cells with fibrils that formed parallel stacks 100 A in diameter and 100 A apart and occupied large areas of the cytoplasm of some cells and an abundance of rough endoplasmic reticulum. The myofibroblast has been reported in a variety of lesions and is also present in granulation tissue and hypertrophic scars. It is postulated, in accordance with previous reports, that myofibroblasts are instrumental in the repair process and that elastofibromas are a product of constant subclinical trauma and repair.