Retinal cavernous hemangioma

Cavernous hemangioma of the retina is an uncommon lesion that resembles a cluster of grapes (Fig 18-3). These lesions may also occur on the optic nerve head. In rare cases, retinal cavernous hemangioma may be associated with similar cavernous angiomatous lesions of the skin and central nervous system that are caused by a mutation in the gene CCM1/KRIT1. Patients with intracranial lesions may experience associated seizures. Given that these lesions are prenatal in origin, cavernous hemangiomas are not typically associated with exudation; thus, treatment is rarely required. However, small hemorrhages as well as gliotic and fibrotic areas may appear on the surface of the lesion. FA may reveal plasma–erythrocyte separation within the vascular spaces of the lesion; this separation is virtually diagnostic of cavernous hemangioma. In contrast to hemangioblastomas, retinal cavernous hemangiomas fill very slowly. The fluorescein remains in the vascular spaces for an extended period without leakage (see BCSC Section 12, Retina and Vitreous).

Figure 18-3 Retinal cavernous hemangioma, clinical photographs. A, Multiple tiny vascular saccules and associated white fibrotic tissue are seen in the retina. B, A smaller lesion consisting of a grapelike cluster of clumped vascular saccules is seen in the macula.

(Part B courtesy of Timothy G. Murray, MD.)

• Choquet H, Pawlikowska L, Lawton MT, Kim H. Genetics of ce rebral cavernous malformations: current status and future prospects. J Neurosurg Sci. 2015;59(3):211–220.

• Gass JD. Cavernous hemangioma of the retina. A neuro-oculo-cutaneous syndrome. Am J Ophthalmol. 1971;71(4):799–814.

Retinal arteriovenous malformations

Congenital retinal arteriovenous malformation (also known as racemose hemangioma) is an anomalous artery-to-vein anastomosis that can occur in the iris, near the optic nerve head, or in the retinal periphery. Clinically, these malformations can range from a small, localized vascular communication to a prominent tangle of large, tortuous blood vessels throughout most of the fundus (Fig 18-4A, B). The term racemose refers to the clustered or bunched nature of the vessels. When associated with an arteriovenous malformation of the midbrain region, this condition is generally referred to as Wyburn-Mason syndrome (also known as Bonnet-Dechaume-Blanc syndrome; see BCSC Section 5, Neuro-Ophthalmology, and Section 6, Pediatric Ophthalmology and Strabismus). Arteriovenous malformations may also appear in the eyelid, orbit, and mandible.

An arteriovenous malformation of the retina is different from a congenital retinal macrovessel, which is a large aberrant retinal vessel that crosses the midline and, often, also the macular area (Fig 18-4C, D). Retinal macrovessels occasionally show arteriovenous communications.

Figure 18-4 Intraocular arteriovenous malformations, clinical photographs. Arteriovenous malformation, or racemose hemangioma, in the iris (A,arrow ) and the retina (B) in 2 patients. C, Although it can occasionally have an arteriovenous communication, a retinal macrovessel is distinct from racemose hemangioma. D, Fluorescein angiogram highlights the macrovessel, which crosses the macular area and the horizontal midline. Absence of leakage is characteristic of retinal arteriovenous malformations.

(Parts A, C, and D courtesy of Tero Kivelä, MD; part B courtesy of Robert H. Rosa Jr, MD.)

• Archer DB, Deutman A, Ernest JT, Krill AE. Arteriovenous communications of the retina. Am J Ophthalmol. 1973;75(2):224–241.

• Heimann H, Damato B. Congenital vascular malformations of the retina and choroid. Eye (Lond). 2010;24(3):459–467.

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.