Renal Cell Carcinoma with Primary Presentation via Metastasis to the Trigeminal Ganglion

Neoplastic nerve lesions

Though metastasis and malignant infiltration of the peripheral nervous system is relatively rare, physicians should have a familiarity with their presentations to allow for prompt diagnosis and initiation of treatment. This article will review the clinical presentations, diagnostic evaluation, and treatment of neoplastic involvement of the cranial nerves, nerve roots, peripheral nerves, and muscle. Due to the proximity of the neural structure traversing the skull base, metastasis to this region results in distinctive syndromes, most often associated with breast, lung, and prostate cancer. Metastatic involvement of the nerve roots is uncommon, apart from leptomeningeal carcinomatosis and bony metastasis with resultant nerve root damage, and is characterized by significant pain, weakness, and numbness of an extremity. Neoplasms may metastasize or infiltrate the brachial and lumbosacral plexuses resulting in progressive and painful sensory and motor deficits. Differentiating neoplastic involvement from radiation-induced injury is of paramount importance as it dictates treatment and prognosis. Neurolymphomatosis, due to malignant lymphocytic infiltration of the cranial nerves, nerve roots, plexuses, and peripheral nerves, deserves special attention given its myriad presentations, often mimicking acquired demyelinating neuropathies.

A most unusual diagnosis via an unusual route: tunneling through Meckel's cave

A 73-year-old woman presented with progressive symptoms of cranial nerve (V, VI, VIII) palsies, ataxia and gait disturbance due to a rapidly growing atypical trigeminocavernous mass. Percutaneous stereotactic transoval biopsy via Hartel's route revealed an exceedingly rare solitary trigeminal metastasis of a clear cell renal cell carcinoma, treated 16 years earlier without any other evidence of systemic disease. A minimally invasive, intra-operatively navigated approach is presented with detailed description of the stereotactic technique and technical considerations. The transoval biopsy expands the surgical repertoire for atypical Meckel cave lesions with diagnostic uncertainty. A frameless navigated technique should be state-of-the-art in contemporary neurosurgical practice.

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.