Diagnostic Criteria for Retinal Hemangioma
Retinal hemangiomas are diagnosed based on characteristic fundoscopic appearance combined with multimodal imaging, with the two main subtypes—capillary hemangiomas (retinal capillary hemangiomas/von Hippel tumors) and cavernous hemangiomas—having distinct clinical and imaging features that allow differentiation.
Retinal Capillary Hemangioma (von Hippel Tumor)
Clinical Features
- Classic triad: retinal capillary tumor with a large feeder arteriole and draining venule 1
- Location: Most commonly in temporal peripheral retina; can also be juxtapapillary 2
- Growth pattern: Endophytic (growing into vitreous) 2
- Appearance: Orange-red vascular mass with prominent feeding and draining vessels 1
Imaging Characteristics
- Fluorescein angiography: Early hyperfluorescence with progressive filling of the tumor and late leakage from the lesion 2
- OCT: Shows elevated retinal mass with associated exudation if present 3
- OCTA: Demonstrates active blood flow within the lesion with visualization of feeding and draining vessels 3, 4
Critical Systemic Evaluation
- Genetic counseling referral is mandatory for all patients with retinal capillary hemangioma, as this is a major manifestation of von Hippel-Lindau (VHL) syndrome 5
- Screen for VHL-associated features: central nervous system hemangioblastoma, clear cell renal cell carcinoma, pheochromocytoma, and endolymphatic sac tumor 5
- VHL screening should be initiated early in the diagnostic workup to enable appropriate systemic surveillance 5
Retinal Cavernous Hemangioma
Clinical Features
- Appearance: Grape-like clusters of dilated vascular sacs with variable surface gliosis 3
- Location: Can occur at optic disc margin or peripheral retina 6
- Characteristics: Rare, benign, congenital vascular malformation that is isolated and non-progressive 3, 4
- Blood flow: Low-stagnant circulation pattern 6
Imaging Characteristics
- Fluorescein angiography: Minimal to no filling of the vascular sacs due to stagnant blood flow; plasma-erythrocyte interface creates fluid levels 4
- OCTA: Shows blood flow within the lesion despite low-stagnant circulation, with clear visualization of vascular abnormalities 4, 6
- OCT: Demonstrates the structural characteristics of the dilated vascular sacs 3, 4
- Blue fundus autofluorescence: Can help characterize the lesion 6
Diagnostic Algorithm
Initial Assessment
- Dilated fundoscopic examination to identify characteristic vascular lesions and document location, size, and associated features 2
- Look for complications: vitreous hemorrhage, pre-retinal traction, macular scarring, exudative retinal detachment 3, 2
Confirmatory Imaging
- Fluorescein angiography remains essential to differentiate capillary from cavernous hemangiomas based on filling patterns 4, 2
- OCTA provides non-invasive, high-resolution visualization of blood flow and vascular architecture, showing good correspondence with FA but with greater sensitivity to vascular abnormalities 4, 6
- Structural OCT to assess retinal architecture, exudation, and macular involvement 3
Mandatory Systemic Workup for Capillary Hemangiomas
- Immediate referral for genetic counseling per American College of Medical Genetics and Genomics recommendations 5
- Comprehensive VHL screening including neuroimaging and abdominal imaging 5
Common Pitfalls and Caveats
- Do not assume isolated retinal findings: Approximately 25% of patients with retinal capillary hemangiomas develop life-threatening von Hippel-Lindau disease 1
- Early detection is critical: Peripheral retinal capillary hemangiomas without exudative detachment have good visual outcomes with early focal laser treatment, but untreated lesions may progress to exudative retinal detachment with poor visual prognosis even after vitreoretinal surgery 2
- OCTA advantages: More sensitive than FA for detecting vascular abnormalities and provides clearer imaging without contrast injection, making it valuable for diagnosis and follow-up 4
- Visual field testing should be performed, particularly for juxtapapillary lesions which may cause visual field defects 6