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**Schwannoma**

Contributors to this article: Pauline Diehl, Carol Hilton, June-Kwon Lee, Anthony Mathenge, Jane Karanja, Tyler Barker, Melinda Collum, Alix Wooten

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Surrounding the nerves in the human body's peripheral nervous system (PNS) is a layer of tissue called the nerve sheath. Contained within this tissue are cells called schwann cells. The cells can develop into either a benign tumor called a schwannoma (the most common of which is an acoustic neuroma) or more rarely a malignant tumor. Although rare, these malignant tumors can occur anywhere in the body. It is seldom painful, despite its origin from nerves, because it is actually a proliferation of the nerve sheath or insulation. It can reach a considerable size, although it usually remains small. The most common areas are the sciatic nerve, the brachial plexus (top of the arm), and the sacral plexus (lower back). This type of tumor when malignant goes by several names - Malignant peripheral nerve sheath tumor, Malignant schwannoma, Neurofibrosarcoma and Neurosarcoma. This is considered a type of soft tissue sarcoma, the entire group of which accounts for less than 1 percent of all new cancer cases each year. This specific type of tumor only accounts for 5 - 7% of all of these cases. ===== 


 * In the above picture (not copyrighted, found at []), the dark circles are schwann cells surrounding PNS axons creating a protective layer known as the myelin sheath. ||

Of special note regarding this tumor, the editor of this page (Alix Wooten) was afflicted with this type of tumor in the left brachial plexar neurovascular bundle. It took five years to diagnose and treat the tumor, which was removed by surgery. Progressing through the five years the function of his left arm and hand was reduced by approximately 60 - 70%, and treatment included narcotics such as oxycontin near the end of the five years to control the pain the tumor caused while impinging on his surrounding nerves and blood vessels. The tumor was 6 cm by 8 cm and was considered very large. We were able to locate a series of pictures that was surprisingly representative of the tumor and surgery he experienced thanks to drnathtumor.com... Please see below.



﻿Risk Factors
Although there is no exact known cause, thus far the risk factors seem to primarily be genetic as soft tissue sarcomas have been linked within families. Schwannomas have also been linked to patients who have a condition known as neurofibromatosis or Recklinghausen's disease, also a rare genetic condition. It is estimated that 50% of the cases are linked to this condition, and another 10% to irradiation.

﻿Clinical Manifestations
These can include
 * A painless swelling or lump in the limb(s) or area affected, usually in the arms or legs
 * Pain or soreness (this can grow severe if the tumor impinges on surrounding nerves and blood vessels)
 * Limping or other difficulty using the arms, legs, feet or hands

﻿Diagnosing Malignant Schwannoma
The definitive procedure for diagnosing a Malignant Schwannoma is to complete a biopsy.

Treatment
<span style="color: black; font-family: 'Times New Roman','serif'; font-size: 12pt;">Surgical intervention is the most common treatment for schwannomas. Because schwannomas are nerve, or neural tumors, a neurosurgeon should perform these surgeries. It is important to have a skilled neurosurgeon in order to have the best possible outcome. When dealing with schwannomas, nerve fibers are involved, which can mean lifelong problems if they are damaged or cut. Neurosurgeons also have sub-specialties or focus areas that they regularly treat. Finding a neurosurgeon with an area of focus matching the location of the tumor further reduces nerve damage risks. Neurosurgeon-oncologists deal with malignant neural tumors, so patients with malignant schwannomas benefit greatly from treatment from this specialty.

<span style="color: black; font-family: 'Times New Roman','serif'; font-size: 12pt;">If a schwannoma is particularly large, the neurosurgeon may choose to use Gamma Knife or reflected solar radiation (FSR) to shrink the tumor. This can be a primary treatment or can shrink the tumor prior to surgery. Smaller tumors are easier to remove and lower the risk of significant nerve damage.

<span style="color: black; font-family: 'Times New Roman','serif'; font-size: 12pt;">Post-surgery, patients often have nerve dysfunction such as numbness, tingling, and pins and needles sensations. Sometimes surgery causes nerve trauma, which leads to temporary nerve pain and sensitivity. If sacrifice of an individual fiber occurs, numbness can be permanent.

<span style="color: black; font-family: 'Times New Roman','serif'; font-size: 12pt;">In the rare event that the schwannoma becomes malignant, chemotherapy and radiation therapy may be employed. Chemotherapy involves the use of anti-cancer drugs administered intravenously. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">Radiation Therapy uses high-energy particles or waves, such as x-rays, gamma rays, electrons, or protons to destroy or damage cancer cells. It works by breaking a strand of DNA molecule inside the cancer cell, which prevents the cell from growing and dividing. Unlike chemotherapy, which exposes the entire body to cancer fighting drugs, radiation therapy is usually a local treatment, affecting only the part of the body being treated. A radiation oncologist recommends and gives the radiation treatment. The patient signs a consent form giving the doctor permission to treat with radiation. A radiation therapy nurse gives patients information about radiation therapy treatment and side effects. The purpose of radiation treatment is to destroy or shrink the tumor, prevent or stop the spread of cancer, and to lessen the chance the cancer may come back. Fatigue is a very common side effect and managing it is an important part of care. Instruct patient to get plenty or rest, and to eat a balanced, nutritious diet.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;"> The patient will need frequent neurological assessments to include LOC, motor abilities, sensory perception, integrated function, and balance and proprioception, especially in the first 48 hours. These results will be compared to baseline assessments to determine the amount of change and need for additional therapy. Additionally, serum electrolytes and osmolality are closely monitored to detect changes in sodium regulation, such as onset of diabetes insipidus and severe hypovolemia. Patients need to be turned and positioned carefully. The patient should not be turned to the side on which surgery was performed. The dressing will be left in place for 3-5 days and will be observed for amount, color, and odor of drainage. Scalp care includes meticulous care of the incision to prevent infection. Preop teaching prepares the patient for the postop period. The patient will be sent to the ICU following surgery. Patients should also be taught what to expect following the procedure. A retrosigmoid approach will require a portion of the head to be shaved, so emotional support is vital. Coping abilities are assessed before surgery to ensure the use of appropriate interventions during the preop and postop periods. The nurse helps the patient maintain function by positioning, mouth and skin care, ROM exercises, bowel and bladder care, and providing for nutritional needs (increased protein and calories to aid in the healing process). Referrals to speech, occupational, or physical therapy may be required to help the patient regain function. The patient who is receiving treatment for a schwannoma needs careful and prompt monitoring of the intracranial pressure (ICP) during the recovery period. Decrease in level of consciousness, restlessness and focal neurologic deficits (i.e. limb deficits) are the earliest warning signs of increased ICP. The PERRLA response and other nursing assessments (increased respiratory rate, temperature, and blood pressure) are late signs of increased ICP and the surgeon should be immediately notified. Nursing measures to stabilize ICP are keeping the head midline (may require use of the cervical collar) and elevation of head should be 30 to 45 degrees. Avoid hip/neck flexion and neck rotation and monitor patient ICP during any patient positioning to determine if routine position changes should be avoided if ICP increases during these changes. The patient should be taught to avoid the Valsava maneuver and may need to be administered stool softeners. If the patient is on mechanical ventilation the nurse should hyperoxygenate the patient prior to suctioning. The nurse should keep the patient in a calm, restful environment with minimal stimuli. Therefore the nurse may need to space out interventions for the patient. Pain assessments and relieving agents are also of vital importance to lowering postsurgical stress. SRS will cause fatigue and poor appetite so the nurse should prepare the patient by encouraging a gradual return to activities and eating a high-calorie, high-protein meal plan to provide as much supplements as possible. The radiotherapy may lead to hair loss and the nurse can discuss prior to surgery options for the patient (i.e. head coverings or scarves) to avoid loss of socialization for the patient. The nurse should also advise the patient during SRS they will need a clear plastic mask placed around their head and neck to determine correct delivery of the treatment. This will relieve anxiety by allowing the patient to prepare for the procedure.

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">﻿References
1. Brooker, C., Nicol, M. (2003). //Nursing Adults: The Practice of Caring.// St. Louis, MO: Mosby Elsevier. 2. Bare, B., Cheever, K., Hinkle, J. and Smeltzer, S. (2009). //Brunner and Suddarth's Textbook of Medical-Surgical Nursing.// Philadelphia, PA: Lippincott, Williams and Wilkins. 3. Lewis, S.L., Heitkemper, M.M., Dirksen, S.R., O'Brien, P.G., & Bucher, L. (Ed.). (2007). //Medical surgical nursing: assessment and management of clinical problems//. Philadelphia, PA: Elsevier. 4. Misra, B.K., Purandare, H.R., Ved, R.S., & Mare, P.B. (2009). Current treatment strategy in the management of vestibular schwannoma. Neurology India, 57(3), 257-263. <span style="color: black; font-family: 'Times New Roman','serif'; line-height: 150%; margin: 0in 0in 0pt;">[] <span style="font-family: 'Times New Roman','serif'; line-height: 150%; margin: 0in 0in 0pt;">[] [] <span style="font-family: 'Times New Roman','serif'; line-height: 150%; margin: 0in 0in 0pt;">[] <span style="font-family: 'Times New Roman','serif'; line-height: 150%; margin: 0in 0in 0pt;">[] <span style="font-family: 'Times New Roman','serif'; line-height: 150%; margin: 0in 0in 10pt;">[]