Ultrastructure of keloid: an unusual incident involving lepromatous leprosy.

A patient with lepromatous leprosy developed keloids on the dorsum of both arms in response to ulcerations due to acute erythema nodosum leprosum reactions. Electron microscopic examination of the keloidal dermis showed a morphology indicative of increased production of normal collagen fibrils. The greatest cellular changes from normal were in fibroblasts which were enlarged due to increased amounts of rough endoplasmic reticulum and extensive Golgi complexes. Nuclear folds were also evident in these fibroblasts. Some cells, considered to be fibroblasts, were filled with cytoplasmic filaments and contained bizarre shaped nuclei. Mast cells, blood vessels and nerve processes were also present.