Morphologic and genetic analysis of retinal angioma associated with massive gliosis in a patient with von Hippel-Lindau disease

We report morphologic and genetic analysis of bilateral retinal angiomas in a 35-year-old patient with von Hippel-Lindau (VHL) disease. Enucleation of both eyes revealed extensive intraocular tumor. Whereas the right eye demonstrated large amounts of retinal angioma tissue, the left eye showed small areas of retinal angioma associated with massive diffuse retinal gliosis. Genetic analysis of the angioma showed allelic deletion of the VHL gene locus, suggesting that the origin of the angiomas was directly related to the patient's underlying VHL disease. Genetic analysis of the pleomorphic glial proliferation showed no allelic VHL gene deletion, which is consistent with the assessment that the glial component represents a reactive process. Apoptosis detected by TUNEL revealed lack of DNA fragmentation in the angioma; in contrast, many positive signals were found in the massive gliosis. We confirmed that the abnormal VHL genes were located in the "stromal" cells of the retinal angioma. Massive gliosis in VHL disease is a true reactive retinal gliosis.