Light and electron microscopic study of early lesions in angiomatosis retinae.

Multiple early untreated lesions of angiomatosis retinae in the peripheral retina and optic disk were discovered after death in both eyes of a patient with von Hippel-Lindau disease. Each of the four peripheral angiomas was studied by a different technique: routine light microscopy of serial histologic sections, electron microscopy, flat mount and trypsin digestion, and frozen section with special stains for lipid. The large capillaries comprising the core of each angioma displayed normal endothelium, basement membrane, and pericytes. Thus, capillary hemangioma of the retina is a more correct histopathologic designation for the von Hippel angioma than terms such as hemangioblastoma or hemangioendothelioma. Interstitial cells separating the vascular channels of the angioma were identified as astrocytes that contain large lipid-filled cacuoles. Serial histologic sections demonstrated that both retinal and choroidal vessels communicate with vascular channels of the juxtapapillary capillary hemangiomas.