Elastic fiber pattern in scleroderma/morphea.

Overview

BACKGROUND: Scleroderma/morphea is characterized by expansion of the dermis with thickened collagen bundles and loss of CD34(+) dermal dendrocytes. Variable elastic fiber changes have been described, but to our knowledge, no systematic study of the elastic fiber pattern correlated with CD34 expression has been reported. METHODS: To better define the typical elastic fiber morphology, we examined seven cases of normal skin and 28 cases of scleroderma/morphea ranging from inflammatory to sclerosing stages. All but four biopsies were submitted with a clinical impression of either scleroderma or morphea. CD34 immunohistochemistry was performed on 26 biopsies with available tissue. RESULTS: Elastic van Gieson stain showed preservation of elastic fibers in all cases. In addition, straightening with parallel orientation and compression between thickened collagen bundles was frequently present and was graded as limited in 46% and diffuse in 54% of cases. The extent of elastic fiber alteration correlated with the degree of sclerosis. A variable loss of CD34(+) dermal dendritic cells was seen in all cases. CONCLUSION: This study confirms the preservation and frequent presence of parallel, straightened and compressed elastic fibers in scleroderma/morphea and suggests that the elastic fiber pattern, in addition to CD34 immunohistochemistry, may serve as a useful diagnostic adjunct.