Multiple Cranial Neuropathies After Lenvatinib-Pembrolizumab Therapy for Metastatic Renal Cell Carcinoma: A Case Report.

Introduction: Multiple cranial neuropathy is a rare manifestation of immune-related adverse events. To date, no cases have been reported during immune checkpoint blockade for metastatic renal cell carcinoma. This report describes a case of multiple cranial neuropathy that developed during lenvatinib and pembrolizumab combination therapy. Case Presentation: A 66-year-old man with metastatic clear cell renal cell carcinoma involving the maxilla received lenvatinib and pembrolizumab. After two months, he developed a rash and facial nerve palsy that resolved with corticosteroids. Pembrolizumab rechallenge later caused diplopia due to multiple cranial neuropathies, which improved after steroid pulse therapy. Two years after treatment initiation, disease control and pembrolizumab maintenance have continued without neurological recurrence. Conclusions: We report a rare case of multiple cranial nerve palsies that developed during lenvatinib-pembrolizumab therapy. Such neuropathies typically occur early, respond to corticosteroids, and require careful monitoring, as retreatment may lead to recurrence or new adverse events.