Renal Cell Carcinoma Metastasis to Meckel's Cave Treated With Repeat Stereotactic Radiosurgery: A Case Report and Review of the Literature.

Renal cell carcinoma (RCC) metastases to Meckel's cave (MC) are a rare condition. To the best of our knowledge, we present the first case of an RCC metastasis to MC successfully treated on two consecutive occasions with stereotactic radiosurgery (SRS). A 57-year-old man presented with new-onset facial pain and numbness. Magnetic resonance imaging (MRI) revealed a lesion invading MC. He was treated with Gamma Knife SRS successfully, resulting in both symptomatic improvement and radiologic tumour regression. Thirteen months after treatment, he presented with a recurrence of trigeminal nerve symptoms. He was treated with hypofractionated SRS successfully, with a follow-up MRI revealing resolution of the disease. While RCC metastases to MC are a rare phenomenon, published literature to date recommends surgical resection in combination with radiotherapy and systemic therapy. Metastatic disease to MC has only been treated once before with radiosurgery alone. Our case demonstrates that repeat SRS is feasible and efficacious. This approach may be favourable in patients wishing to avoid risks of surgical resection, or for those with unresectable disease. Metastases of RCC to MC are a rare occurrence and typically present with facial pain and/or hypoesthesia. This case demonstrates that repeat radiosurgery may be an effective alternative to surgical resection.