Electron‐microscopic Study of Sclerodermatous Chronic Graft‐versus‐host Disease

BACKGROUND: Sclerodermatous chronic graft-versus-host disease (SC-GVHD) resembles systemic scleroderma (SSD) closely, both clinically and histologically. Our purpose was to try to define the morphologic differences of collagen fibers between SC-GVHD and SSD. MATERIALS AND METHODS: Using electron microscopy, we compared the morphology of collagen fibers in a 15-year old girl with SC-GVHD with those of three patients with SSD. RESULTS: In SC-GVHD, sclerosis is located in the superficial dermis and collagen fibers of irregular diameter are seen in the subepidermal area. In SSD, sclerosis is seen in the lower dermis and subcutaneous fatty tissue, and collagen fibers of irregular diameter are located in the deep dermis. Some of the collagen fibers were degenerative in the superficial dermis in SC-GVHD. We observed low-density, round structures in cross sections of collagen fibers. CONCLUSIONS: The difference in initial location and morphologic appearance of collagen fibers may indicate a different pathogenesis in SC-GVHD compared to SSD.