Retinal Capillary Haemangioblastoma: Clinical Spectrum, Imaging Insights, and Treatment Strategies.

Background: Retinal capillary haemangioblastoma (RCH) is a benign but potentially vision-threatening vascular tumour of the retina. It may occur sporadically or as multifocal, bilateral lesions in association with von Hippel-Lindau (VHL) disease, often serving as the first manifestation of this multisystem disorder. The pathogenesis involves dysregulated angiogenesis through hypoxia-inducible factor (HIF) pathways, resulting in capillary proliferation and stromal recruitment.

Summary: RCHs may present as asymptomatic peripheral lesions or as juxtapapillary tumours, leading to exudation, retinal detachment, and vision loss. Classification based on anatomical location and growth pattern (endophytic, exophytic, sessile) aids prognostication and treatment planning. Diagnosis relies on multimodal imaging, including fluorescein angiography, optical coherence tomography (OCT), OCT angiography, and occasionally indocyanine green angiography. Treatment is individualized according to tumour size, location, and complications, ranging from laser photocoagulation, cryotherapy, photodynamic therapy, and intravitreal anti-vascular endothelial growth factor (VEGF) injections to vitrectomy for tractional complications. Recently, systemic HIF-2α inhibitors such as belzutifan have shown promise in stabilizing retinal lesions in VHL patients. Accurate differentiation from mimickers such as vasoproliferative tumours, Coats disease, and cavernous haemangiomas remains essential.

Key messages: RCH is often the first sign of VHL disease, highlighting the need for systemic evaluation. Its pathogenesis stems from HIF pathway dysregulation, with tumour size and location - especially juxtapapillary lesions - determining visual risk. Multimodal imaging is vital for diagnosis, differentiation, and monitoring. Management is individualized, using focal therapies, anti-VEGF injections, or surgery for complications, while systemic HIF-2α inhibitors like belzutifan show promise in VHL-associated cases. Early detection and a multidisciplinary approach are essential for preserving vision and managing systemic disease.