An analysis of conjunctival and periocular venous malformations: clinicopathologic and immunohistochemical features with a comparison of racemose and cirsoid lesions

Vascular tumors (in contrast to dilations or ectasias) of the conjunctiva and other adnexal tissues are rare, with no previous convincing example of a congenital, purely venous conjunctival malformation having been described. A 33-year-old man with a previously well-tolerated racemose conjunctival lesion present from birth developed bothersome symptoms when it underwent multifocal thrombosis with papillary endothelial cell hyperplasia as part of the process of thrombotic organization. Conservative subtotal excision with placement of an amniotic graft led to an acceptable cosmetic appearance, abatement of symptoms, and retention of full ocular function. Histopathologically, the lesion was composed of patulous vascular channels with thin walls displaying a negligible and irregular muscularis, diffuse supportive mural fibrosis, and the absence of an elastic lamina. Immunohistochemically the endothelial cells were CD31- and CD34-positive (vascular origin) but D2-40-negative (lymphatic origin). An associated neovascular capillary bed was not detected. Venous (racemose or grape-like) malformations should be distinguished from: arteriovenous (cirsoid or twisted) malformations in which the vessels possess thicker and more uniform muscular walls, some of which are endowed with an elastica; varices (hemorrhoidal dilations typically of a pre-existent vein); and venous angiomas (noncongenital lesions acquired in middle life) composed of regularly structured muscular channels devoid of an elastic lamina. Other conditions not to be confused with congenital venous malformations include hemorrhagic lymphangiectasia (of Leber), hemorrhagic lymphangiomas, and complex lymphaticovenous malformations.