Renal cell carcinoma: a rare source of cauda equina metastasis. Case report

Clinical Features and Neurosurgical Management of Metastatic Intradural Extramedullary Renal Cell Carcinoma

Intradural extramedullary metastasis of renal cell carcinoma is exceedingly uncommon, and only 19 cases have been reported in the literature. It is thought to metastasize from the kidneys through venous networks or along nerves and may also spread from brain metastases through cerebrospinal fluid. We present a 52-year-old female, two years after a nephrectomy with myelopathic symptoms, who was found to have thoracic intradural extramedullary metastasis from renal cell carcinoma. The thoracic tumor was resected without any added deficit, but an additional brain mass was found on postoperative imaging. The present case and a literature review were discussed to explore considerations for neurosurgical intervention in similar patients, evaluate surgical outcomes, and highlight current theories on routes of metastasis. Given the risk of neurological decline in patients with metastatic intradural renal cell carcinoma, surgical resection should be considered upon its discovery, and postoperative surveillance imaging is encouraged.

The Role of Surgery in Spinal Intradural Metastases from Renal Cell Carcinoma: A Literature Review

BACKGROUND

Due to the few reported cases of spinal intradural metastases from renal cell carcinoma (RCC), there is no unanimous consensus on the best treatment strategy, including the role of surgery.

METHODS

A wide and accurate literature review up to January 2022 has disclosed only 51 cases of spinal intradural metastases from RCC. Patients with extramedullary (19) and those with intramedullary (32) localization have been separately considered and compared. Demographics, clinical, pathological, management, and outcome features have been analyzed.

RESULTS

Extramedullary lesions more frequently showed the involvement of the lumbar spine, low back pain, and solitary metastasis at diagnosis. Conversely, the intramedullary lesions were most often detected in association with multiple localizations of disease, mainly in the brain. Surgery resulted in improvement of clinical symptoms in both groups.

CONCLUSION

Several factors affect the prognosis of metastatic RCC. The surgical removal of spinal metastases resulted in pain relief and the arresting of neurological deficit progression, improving the quality of life and overall survival of the patient. Considering the relative radioresistant nature of the RCC, the surgical treatment of the metastasis is a valid option even if it is subtotal, with a consequent increased risk of recurrence, and/or a nerve root should be sacrificed.

Metastatic Renal Cell Carcinoma Mimicking Trigeminal Schwannoma in a Patient Presenting with Trigeminal Neuralgia

We present an unusual case of a metastatic renal cell carcinoma (RCC) mimicking trigeminal schwannoma. The patient, with no prior history of RCC, presented with clinical symptoms and imaging consistent with trigeminal neuralgia secondary to trigeminal schwannoma. Magnetic resonance imaging of the brain showed a large bilobed cystic/solid mass primarily in the cerebellopontine angle cistern, with extension into the left middle cranial fossa, Meckel cave, and left cavernous sinus. Following surgical excision, histopathology revealed the tumor to be an RCC infiltrating into the trigeminal nerve fascicles. Further imaging and investigation revealed widespread metastasis to the vertebral bodies and long bones. Metastatic RCC to the trigeminal nerve is rare. Despite the development of more effective treatment modalities, the prognosis of metastatic RCC remains poor. To our knowledge, this is the first reported case of RCC metastasizing to the trigeminal nerve fascicles.

Surgical treatment options and management strategies of metastatic renal cell carcinoma to the lumbar spinal nerve roots

Spinal nerve root metastasis of renal cell carcinoma is a rare occurrence. In addition to treatment of the primary lesion, surgical resection of the nerve root metastasis, occasionally with sacrifice of the involved nerve, is the accepted standard of treatment. Resection often resolves presenting motor and pain symptoms due to relief of neural compression. We describe two patients with nerve root metastasis of renal cell carcinoma and their management. While locally advanced and metastatic renal cell carcinoma has been shown to be chemo- and radio-resistant, immunotherapy is a promising treatment. Given the high prevalence of systemic disease in patients with intradural metastases, systemic (and possibly intracranial) imaging can be used to identify other potential areas of disease.

Treatment strategies of space-occupying intradural metastases of the cauda equina of nonneurogenic origin

BACKGROUND

Compressive intradural metastases of the cauda equina are a rare site of metastatic spread in systemic cancer. So far, only few reports have been published with conflicting statements concerning a surgical versus nonsurgical approach.

METHOD

Five patients with symptomatic space-occupying intradural metastases of the cauda equina were analyzed retrospectively, focusing on the influence of surgical intervention on pain relief, neurological outcome and thus the patients' quality of life.

FINDINGS

At the time of diagnosis, all patients were in an advanced metastatic state. Surgical resection was the primary treatment in four patients and radiotherapy in one. Despite infiltration of the cauda rootlets, gross total tumour resection could be achieved in two of the four patients treated surgically. Functional outcome was beneficial in these patients with marked and immediate relief of pain and improvement of motor function even following incomplete tumour resection.

CONCLUSIONS

Surgical treatment of compressive intradural metastases of the cauda equina seems to be feasible with low operative risk and with the potential benefit of an immediate relief of pain and improvement in motor function and thus an increase in quality of life.

Spinal metastasis of occult lung carcinoma causing cauda equina syndrome

Cauda equina syndrome (CES) may be caused by tumor, herniated disc, trauma and spinal infections. However, CES due to occult lung cancer has not been reported in the literature. A 50-year-old man presented with a subacute CES caused by an intradural metastasis of an adenocarcinoma of the lung to the lumbosacral cauda fibers. His lumbosacral magnetic resonance imaging (MRI), showed a well-demarcated, intradural extramedullary mass lesion resembling a neurinoma at the L4/5 level. The patient underwent an L4-L5 laminectomy. The operative findings were also suggestive of neurinoma with involvement of three nerve roots, and a well-demarcated tumor without infiltration into the subarachnoid space. Although the findings of the operation were suggestive of neurinoma, final pathological diagnosis revealed metastatic carcinoma. Immunohistochemistry revealed clear cell adenocarcinoma metastasis. Chest X-ray and high resolution contrasted pulmonary computed tomography were normal. Positron emission tomography (PET) showed a lung mass, at the left apex. The patient was treated with chemotherapy and post-operative spinal radiotherapy was also performed. The CES resolved after the operation and the patient was followed up for 2 years with no recurrence. MRI of intradural cauda equina metastasis may be similar to that of intradural nerve sheath tumor. Surgery and postoperative radiotherapy may be effective for the treatment of CES due to lung carcinoma. Definitive diagnosis is by histopathological examination with immunohistochemistry. If the primary cancer cannot be detected by conventional radiological techniques, PET may be helpful.

Intradural spinal metastasis from renal cell carcinoma: A case report

Intradural spinal metastasis is rare. This is the third case ever reported on the finding of intradural spinal metastasis from a renal cell carcinoma that had been removed surgically. The patient had a history of epidural metastasis for which excision and anterior stabilization were done 3 years before the new presentation with cauda equina lesion. Seeding from the involved osseous structure to the cerebrospinal fluid through the dura was believed to be the course that tumour had taken to reach the intradural space.