Tumors are formed from abnormal excessive cell division in the body and when this occurs in nerve tissue it is called neuroma. These tumors can be formed on the peripheral nerves, the nerves that link the brain and spinal cord to the rest of the body. The tumors may be benign or malignant. Benign tumors are non-cancerous and do not spread to the surrounding tissues or cells. Malignant tumors are cancerous and spread to other tissues or cells. Neuromas are usually benign.
Nerve biopsy is performed to determine if the neuroma cells are benign or malignant. Other diagnostic tests your doctor may order include magnetic resonance imaging (MRI), computed tomography (CT) scan, or electromyography (EMG).
Symptoms depend on the location of the neuroma. The neuroma may cause pain, numbness in limbs, difficulty in moving your arms and legs, weakness in the affected area, and loss of balance.
The various types of nerve tumors include
- Dumbbell tumor
- Ganglion cyst
Neurofibromas are common benign tumors which occur most often on the nerves that are in the skin or just below the skin. Neurofibromas are more common in young adults. They occur as painless, solitary masses or rarely as multiple masses, on peripheral nerves, soft tissues, skin surfaces or bone.
Schwannoma tumors are benign, slow growing tumors made up of Schwann cells that occur on the protective sheath (outer covering) of the nerve fibers. Schwann cells are responsible for producing the myelin sheath that covers peripheral nerves. They are often found around the cranial or spinal nerves. They are mostly non-cancerous and acoustic neuroma, which can cause deafness, is the most common benign schwannoma. Acoustic neuroma, also called vestibular schwannoma, is a tumor of the vestibulocochlear nerve, the 8th cranial nerve, which controls hearing. Although rare, malignant schwannomas can occur and are more common on the sciatic nerve (nerve in leg), brachial plexus (nerve at top of the arm), and sacral plexus (nerves on lower back).
Dumbbell tumors are rare schwannomas that often resemble a dumbbell. They can appear in spine, lower abdomen, hip, or pelvic region. They are challenging to surgically remove because the tumor tissue is often very intertwined with major nerves.
Lipoma – These are slow growing benign tumors formed under the skin from lipid (fat) cells. They often appear on the neck, shoulder, back, and arms. Lipomas are usually without symptoms but can compress nerves nearby.
Ganglion cyst – These are non cancerous raised lumps typically found near joints such as the wrist and fingers, but can occur anywhere on the body. When ganglion cysts compress nearby nerves, surgical removal is indicated.
Treatment of Neuromas
Surgery is usually the most appropriate treatment for benign peripheral nerve tumors as it often prevents recurrence of the tumor. However, if the tumor is not causing symptoms, your physician may want to take a “wait and see” approach and observe the growth of the tumor with imaging tests and regular checkups.