Schwann cells wrap around the peripheral nerves, offering some kind of insulation. Tumor of the Schwann cells is called Schwannoma. It is mostly slow growing and benign.
Introduction to Schwannoma
A special type of cells called Schwann cells (named after physiologist Theodor Schwann who discovered it) wrap around peripheral nervous system, acting like insulation around wires. This insulation is also called myelin sheath.
Overgrowth of the Schwann cells form into a tumor called Schwannoma. When the early surgeons realized that Schwannomas contained many nerve fibers within them. So, Schwannoma is also called neurofibroma (nerve fiber + (oma = tumor)).
Schwannomas grow very slowly and they are almost always benign. Less than 1% of Schwannomas become malignant. When they do, they are called neurofibrosacroma (nerve fiber + (sacroma = a type of cancer)).
Cells in a Schwannomas are smooth and spindle shaped, tapering on both ends and bulging in the center.
Complication due to Schwannoma
Schwannomas grow slowly. They are mostly benign. So, life-threat from Schwannomas is rather low.
However, when the tumors grow, they compress on the nerves touching the tumor, causing various complication from headache to loss of sensation.
There is also a tiny risk of a Schwannoma turning into a neurofibrosarcoma.
Symptoms of Schwannoma
The symptoms of a Schwannoma depends on the location and size of the tumor.
Following symptoms are seen if the Schwannoma occurs in the brain:
- Gait problems
- Speech disturbances
If the tumor occurs in the spinal cord, depending on the spot, symptoms vary. Common symptoms are:
- Back pain, increasing while lying down
- Muscle weakness
- Lack of sensation in one or more parts of the body
- Difficulty moving arms and/or legs
- Thinning of the muscles of the hand
- Hip pain
- Pain radiating to the legs
- Tingling or pricking sensation of legs
- Gait problems
- Loss of control over stools
- Loss of bladder control
- Impaired sexual functions
- If the tumor is located in the nape region, then nausea, vomiting and headache
Diagnosis of Schwannoma
When Schwannoma is suspected through clinical evaluation, one or more of the following imaging studies are ordered to ascertain the initial diagnosis:
- MRI Imaging
MRI is the best imagign modality to diagnose Schwannomas. Using an MRI, even small tumor can be detected at an early stage.
- MRI Neurography
MRI Neurography is a specialized imaging technique used to make a picture of the nerves. These reports show the extent of nerve involvement.
Treatment for Schwannoma
Here are the options available for treating Schwannomas.
Steroid medication help to an extent to remove any fluid accumulation in the location of the tumor. Pain relievers are used to reduce the pain felt by the patient when the tumor starts compressing the nerves.
Total Microsurgical Resection: This is the treatment of choice for Schwannomas. This procedure involves careful and meticulous removal of tumor using tiny surgical instruments and microscopes. Go here for more information on Total Microsurgical Resection.
Following the surgery, a radiotherapy is usually ordered in order to prevent recurrence of the tumor in the future.
Since Schwannomas are generally not life threatening, a surgeon might decide to wait out till the time the symptoms of Schwannomas become debilitating.
There is growing scientific evidence that long term usage of steroids and pain medication result in future complications. So, there is a tendency to remove the tumor sooner than later.