SUCCESSFUL TREATMENT OF VON HIPPEL-LINDAU DISEASE-ASSOCIATED RETINAL CAPILLARY HEMANGIOBLASTOMA WITH BELZUTIFAN IN A PEDIATRIC PATIENT.

Purpose: The authors describe a case of a retinal capillary hemangioblastoma (RCH) in a pediatric patient with von Hippel-Lindau (VHL) syndrome that was successfully treated with systemic belzutifan.

Methods: The clinical course was documented with serial fundus examinations and multimodal imaging, including Optos widefield fundus photography and optical coherence tomography. A literature review was conducted to look for similar cases and/or discussion.

Results: A left RCH was noted on a standard VHL surveillance retinal examination of a then 15-year-old male patient with VHL syndrome. Over the course of 17 months, this RCH was treated with focal laser therapy, photodynamic therapy, cryotherapy, bevacizumab injection, and endolaser ablation. Complications of these treatments included subretinal fluid and vitreomacular traction necessitating laser retinopexy, scleral buckle, and pars plana vitrectomy with membrane stripping. After a 6-month interval from the last local therapy (endolaser treatment), there was minimal regression of the lesion, and many concerning features persisted. At 22 months from presentation, the patient started belzutifan 120 mg PO daily with subsequent regression in size and less perfusion to the hemangioblastoma within 4 months. The patient is tolerating the systemic belzutifan with only the expected normocytic anemia and has not required transfusion therapy after 12 months of treatment.

Conclusion: von Hippel-Lindau disease is a rare and serious condition associated with multiple types of benign and malignant tumors. Belzutifan is tolerated in the adolescent population and can provide a systemic treatment alternative for VHL-associated RCH.