Tumors, masses, or growths that are benign or cancerous may cause sciatica-like signs and symptoms if they occur in the lower spine or on the sciatic nerve (nerve tumors). Tumors of any type are a medical emergency and must be monitored and/or treated immediately. Depending on the patient’s age, overall health condition, and level of tolerance, surgical or other medical treatment may be performed.

Tumors growing within the vertebrae can make the spinal bones weak, causing them to break and collapse. Watch: Metastatic Spinal Cancer Video

Spinal Tumors

A spinal tumor is an abnormal mass of cancerous or noncancerous tissue that surrounds the spinal cord or spinal column. Spinal tumors are classified based on their locations within or outside the dura (covering of the spine). Intradural tumors usually develop within the spinal cord, nerves, or their coverings (dura), while extradural tumors usually are metastases from other parts of the body. Lumbar or sacral spinal tumors can cause back pain and leg weakness as seen in sciatica; leg pain may also be present.

Diagram showing three types of spinal tumors: extradural, intradural-extrmedullary, intramedullary

Spinal tumors are classified based on their location within or outside the dura and spinal cord. Extradural tumors are located outside the dura, intradural-extramedullary tumors are inside the dura but outside the spinal cord, and intramedullary tumors grow inside the spinal cord.



Differentiating signs and symptoms may include one or more of the following:

  • Severe night pain in the back and/or legs
  • Loss of bowel and/or bladder control
  • Unexplained weight loss and/or loss of appetite
  • Loss of sensation in one or more parts of the legs

If spinal tumors are detected early, they may be removed in order to prevent the tumor from increasing in size. If cancer exists in other parts of the body, additional considerations may take precedence.

Read more about Symptoms of a Spinal Tumor

Metastatic Spinal Cord Compression

Medical illustration showing a metastatic tumor in the spinal column

Metastatic spinal cord tumors develop when cancer cells from other parts of the body, such as the breast, kidney, or lung, migrate through the bloodstream and become lodged in the spine. Most metastatic spinal tumors occur in the thoracic spine.

Metastatic spinal cord compression occurs when cancer cells from other parts of the body migrate (mainly through the bloodstream) and get lodged in the spine. The cells rapidly grow, compressing the spinal sac, the spinal cord, and/or the cauda equina causing pain and other symptoms. While this condition is most likely to occur in patients who already have a cancer diagnosis, research indicates that 23% of patients may experience pain from metastatic spinal cord compression without a prior cancer diagnosis. 1 National Collaborating Centre for Cancer (UK). Metastatic Spinal Cord Compression: Diagnosis and Management of Patients at Risk of or with Metastatic Spinal Cord Compression. Cardiff (UK): National Collaborating Centre for Cancer (UK); 2008 Nov. (NICE Clinical Guidelines, No. 75.) 4, Early detection. Available from: https://www.ncbi.nlm.nih.gov/books/NBK55008/ , 2 Al-Qurainy R, Collis E. Metastatic spinal cord compression: diagnosis and management. BMJ. May 2016:i2539. doi:10.1136/bmj.i2539

Compression of the lumbar spinal cord from metastatic cancer cells may result in sciatica pain and other signs and symptoms, such as progressive numbness and weakness in the legs.

Additionally, some combination of the following symptoms and signs may be present:

  • Tenderness in the low back
  • Heaviness, cramping, and/or numbness in the legs
  • Sexual dysfunction
  • Loss of bowel and/or bladder control
  • Progressive weight loss
  • Nausea and/or loss of appetite

Unlike sciatica, the symptoms of metastatic spinal cord compression typically occur in both legs. Early diagnosis and treatment of this condition can prevent permanent nerve damage.

Read more about Metastatic Spinal Tumor Symptoms

Schwannoma of the Sciatic Nerve

Schwannoma is a benign tumor that develops from the sheath that surrounds a nerve. The lesion may occur in one region of the nerve or all along the course of the nerve. When this condition affects the sciatic nerve, sciatica pain occurs. The pain typically follows the course of the nerve affecting the lower back, thigh, legs, and/or feet. If the tumor grows, the symptoms may become severe.

While not common, it is possible for schwannoma to become malignant. Both benign and malignant schwannomas must be surgically removed in order to prevent severe neurological deficits and/or complete loss of nerve function. 3 Rhanim A, El Zanati R, Mahfoud M, Berrada MS, El Yaacoubi M. A rare cause of chronic sciatic pain: Schwannoma of the sciatic nerve. J Clin Orthop Trauma. 2013;4(2):89–92. doi:10.1016/j.jcot.2013.04.001


Prostate Cancer

A cancerous tumor in the prostate gland can cause back and leg pain, and weakness in the legs and feet, as in sciatica. 4 Hansen JM, Rasti Z, Smith T, Lassen LH. Sciatic neuropathy as first sign of metastasising prostate cancer. BMJ Case Rep. 2010;2010:bcr1220092529. Published 2010 Oct 11. doi:10.1136/bcr.12.2009.2529 Symptoms and signs of prostate cancer that differ from sciatica may include:

  • Problem urinating, especially at night
  • Erectile dysfunction
  • Pain in the hips and/or chest (if cancer has spread to the bones)
  • Blood in the urine and/or semen

It is possible for these symptoms to be caused by cancerous or noncancerous growths in the prostate gland.

As a general rule, it is advised to consult a doctor when troubling signs and symptoms occur along with sciatica. A doctor can accurately evaluate, diagnose, and treat the underlying cause, preventing the progression of the condition.

See Specialists Who Treat Back Pain

Dr. Jay Jagannathan is a neurosurgeon specializing in spine surgery, and he is the Founder and President of a Michigan-based multidisciplinary practice offering neurosurgery, neurology, and pain management services.

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