Histopathological and ultrastructural features of dermal telangiectasias in systemic sclerosis

Abstract

To investigate the histological, ultrastructural and immunohistochemical features of the vascular lining of dermal telangiectasia, a characteristic clinical finding in scleroderma. Standard histological, electron microscopic and immunohistological techniques were used to examine dermal telangiectasias in five patients with limited scleroderma, the most common scleroderma variant in Caucasian populations. The telangiectasias were dilated postcapillary venules located in the papillary and superficial reticular dermis. The vessel walls consisted of non-fenestrated endothelial cells surrounded by a variable number of pericytes and smooth muscle cells. There were no unique ultrastructural features. Thickened collagen fibres in the reticular or deep dermis were seen in all but one patient, although in variable and generally minimal quantities. Surrounding infiltrating inflammatory cells were scarce. No enhanced endothelial staining was obtained with antibodies directed against endoglin, endothelin, E-selectin and ICAM-1 suggesting a resting or inactivated state. The immunohistological and ultrastructural features of the lining endothelium of established telangiectasias in long-standing, limited scleroderma appear benign. It would be of interest to examine telangiectasias in the early phase of their formation. Alternatively, other explanations need to be explored in understanding the aetiopathogenesis of telangiectasia in scleroderma.