Endolymphatic Sac Tumors Associated With von Hippel–Lindau: A Case Report Highlighting Opportunity for Novel Orphan Drug Therapy

Abstract

Objective To discuss the potential benefit of belzutifan therapy in a patient with von Hippel–Lindau (VHL) disease–associated endolymphatic sac tumor (ELST). Patients Case report. Interventions Clinical details of a patient with residual ELST after hearing preservation surgery who initiated belzutifan therapy postoperatively for concurrent renal cell carcinoma, as well as literature review of belzutifan and ELST. Main Outcome Measures The patient remained without radiologic evidence of growth of her residual tumor at 17 months post-initiation of belzutifan. It is unknown whether this represents therapeutic drug effect, nonviability of residual tumor, or slow tumor growth not captured radiographically within the duration of follow-up. Conclusions Belzutifan could have direct therapeutic benefit in patients with VHL-associated ELST.