Expression of inhibin α by stromal cells of retinal angiomas excised from a patient with von Hippel-Lindau disease

Abstract

To report the results of immunohistochemical analyses of a retinal angioma obtained from a patient with von Hippel-Lindau (VHL) disease. A 13-year-old girl with VHL disease presented with bilateral retinal angiomas and decreased vision in the right eye. Although transpupillary thermotherapy was performed to treat the angiomas, the tractional and exudative retinal detachment progressed OD, requiring vitreous surgery. Intraoperatively, a large retinal angioma was excised together with the surrounding retina to aid in reattaching the retina. The excised tissue was prepared for standard histopathology and immunohistochemistry. Histological examination showed that the excised tissue was made up of highly vascularized cells, and the retina was gliotic. The stromal cells had intracytoplasmic vacuoles and were located between the numerous vessels. These findings are identical to those of a hemangioblastoma. The stromal cells stained positively for vascular endothelial growth factor and neuron specific enolase, and weakly for glial fibrillary acidic protein. Some of the stromal cells stained positively for inhibin alpha. Isolated erythropoietin-positive cells, indicative of developmentally arrested angioblasts, were observed among the endothelial cells. The results indicate that stromal cells in retinal angiomas are neuroectodermal in origin with immunohistochemical features, for example, inhibin alpha, similar to cerebellar hemangioblastomas and renal cell carcinomas associated with VHL disease.