Generalized racemose livedo with cerebrovascular lesions (Sneddon syndrome): an occlusive arteriolopathy due to proliferation and migration of medial smooth muscle cells.
We describe two cases of livedo racemosa generalisata with cerebrovascular defects (Sneddon syndrome). The histology is characterized by a proliferation and migration of medial smooth muscle cells in ascending arterioles of the upper subcutis and deep dermis. Migrating smooth muscle cells with a high content of intermediate filaments colonize the sub-endothelial intimal space, with subsequent narrowing of the vessel lumen. Since the discoloration of the skin is provoked by a reactive dilatation of venules, the biopsy should be performed in the adjacent normal-looking skin, taking in the upper subcutis.
D000328:Adult; D001157:Arterial Occlusive Diseases / Q000473:pathology*; D001160:Arterioles / Q000648:ultrastructure; D002455:Cell Division; D002465:Cell Movement; D002561:Cerebrovascular Disorders / Q000473:pathology*; D005260:Female; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000648:ultrastructure*; D012867:Skin / Q000098:blood supply*; D012871:Skin Diseases / Q000473:pathology*; D013577:Syndrome