Numerous developmental anomalies may be observed in the retinal vasculature, including Coats disease and hemangioblastoma. In Coats disease, exudative retinal detachment is due to leakage from abnormalities in the peripheral retina, which include telangiectatic vessels, aneurysms, and saccular dilatations of the retinal vessels (Fig 11-4). Histologically, retinal detachments secondary to Coats disease are characterized by “foamy” histiocytes and cholesterol crystals in the subretinal space (see Fig 11-4E).
Figure 11-4 Coats disease. A, Leukocoria in a patient with Coats disease. B, Fundus photograph demonstrating multiple retinal macroaneurysms and lipid exudate. C, Total exudative retinal detachment in Coats disease with dense subretinal proteinaceous fluid (asterisk).D, Telangiectatic retinal vessels (asterisks) and “foamy” histiocytes (arrowhead) typical of Coats disease. E, High-magnification of subretinal exudate showing lipid-laden and pigment-laden histiocytes (arrows) and cholesterol clefts (arrowheads).
(Parts A, C, and D courtesy of Hans E. Grossniklaus, MD; part B courtesy of Benjamin J. Kim, MD; part E courtesy of George J. Harocopos, MD.)
Figure 11-5 Retinal capillary hemangioblastoma in von Hippel–Lindau syndrome. A, Low-magnification photomicrograph showing a retinal tumor with a thick-walled feeder vessel (arrow) and a cystic area filled with proteinaceous material (asterisk). Note the prominent blood vessels and area of dense cellularity composed of stromal cells (periodic acid–Schiff [PAS] stain). B, Higher magnification showing the numerous small, capillary-like vascular channels (arrows). The vacuolated, foamy stromal cells (arrowheads) are the tumor cells that have the VHL gene mutation.
(Courtesy of Robert H. Rosa Jr, MD.)
Retinal capillary hemangioblastoma is a vascular tumor that is often seen in patients with von Hippel–Lindau (VHL) syndrome (see Chapter 18). These tumors are composed of many abnormal, capillary-like, fenestrated channels surrounded by vacuolated, foamy stromal cells and reactive glial cells (Fig 11-5). Histologically, retinal and optic nerve hemangioblastomas are similar to hemangioblastomas of the CNS. Loss of heterozygosity of the VHL gene has been clearly identified in the vacuolated stromal cells but not in the vascular endothelial or reactive glial cells of retinal and optic nerve hemangioblastomas. Thus, the vacuolated, foamy stromal cells are the actual neoplastic cells of the retinal hemangioblastomas.
See BCSC Section 12, Retina and Vitreous, for further discussion of these vascular anomalies and their clinical features.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.