[JNUS]

Renal cell carcinoma (RCC) is known to produce solitary metastatic deposits even after radical nephrectomy. Although the findings are based on relatively few cases, one retrospective study reported a mean duration of 3.9 years for the formation of a solitary metastatic deposit after a radical nephrectomy for renal cell carcinoma.1 Currently, the preferred therapy for metastatic deposits is radical surgery. Radical radiotherapy is of unclear efficacy, showing a potential benefit in a few studies.2 Other modes of therapy, including immunotherapy with interleukins and interferons, have been utilized with inconsistent results. Up to one third of patients with RCC have metastases at the time of presentation. Of the remaining patients who do not present with metastases, approximately 50% will have metastatic disease after a radical nephrectomy.3 Research of new agents and treatments to identify improved anti-tumor activity against metastases remains a high priority in this refractory disease.

The phenomenon of solitary metastasis in RCC has been the subject of several studies and case reports. The frequency of solitary metastases is less than 5%.13 Patients who develop a single metastasis after removal of the primary tumor appear to have a better chance of recovery and long-term survival than patients who present with a metastasis along with the primary tumor.3,5 Interestingly, one article from Japan reported a case of spontaneous regression of sternal metastases that had developed after a radical nephrectomy. 5

Epidural spinal cord compression as a result of metastatic cancer is a commonly seen complication of certain types of cancers (most typically, lymphoma, lung cancer, breast cancer, and prostate cancer). Other causes of epidural spinal cord compression include certain other types of cancers, such as melanoma and renal cell cancer (as in this case), and other nonmalignant etiologies, such as vertebral subluxation and spinal epidural hematoma. The metastatic lesions usually extend into the spinal canal to compress the spinal cord after initial metastasis to the vertebral body. The majority of cases occur in the thoracic spine (68%), with the remainder being in the cervical spine (15%) and in the lumbar spine (19%). In most patients, insidious back pain over a period of weeks to months is the typical presentation, as in this case. Other common presenting symptoms and signs include weakness, hyporeflexia or hyperreflexia, and sensory abnormalities.8

In cases of suspected spine metastases for back pain in high-risk groups (eg, the elderly, as well as patients with a prolonged duration of pain, a history of cancer, or a non-traumatic etiology), plain film radiographs are reported to be up to 90% sensitive for detecting tumor in the vertebral bodies, but CT is more sensitive and may be required for cases with unexplainable symptoms. Additionally, when the diagnosis is made by screening plain radiographs, CT scanning may be performed to better define the lesion. When spinal cord compression is suspected, MRI is the diagnostic modality of choice for evaluation.

In cases of confirmed spinal cord compression, immediate treatment is necessary. High-dose steroids should be begun to reduce inflammation and edema. Consultation for radiation therapy should be sought without delay, taking into account factors such as the location of the compression, the radiosensitivity of the tumor (if known), and the rate of decompensation. Surgical therapy is indicated in cases of diagnostic uncertainty, spine instability, and post-radiation.

The patient in this case was first treated with radical radiotherapy. After 1 month of radiotherapy there was no clinical improvement in the patient’s condition. Considering the patient’s age and other comorbidities, and as per the patient’s own feelings, the decision was made to forego surgery. The patient is currently in a nursing home, and no further cycles of radiotherapy are being considered at this time.