Malignant peripheral nerve sheath tumor
Encyclopedia
A malignant peripheral nerve sheath tumor (also known as "Malignant schwannoma," "Neurofibrosarcoma," and "Neurosarcoma") is a form of cancer
of the connective tissue
surrounding nerve
s. Given its origin and behavior it is classified as a sarcoma
. About half the cases are diagnosed in people with neurofibromatosis
; the lifetime risk for an MPNST in patients with neurofibromatosis type 1 is 8-13%. MPNST with rhabdomyoblastomatous component are called Malignant triton tumor
s.
The first-line treatment is surgical resection with wide margins. Chemotherapy
(e.g. high-dose doxorubicin
) and often radiotherapy
are done as adjuvant and/or neoadjuvant treatment.
(a tumor suppressor gene in the normal population) genome on 17p in neurofibrosarcoma patients is mutated, increasing the probability of cancer. The normal p53 gene will regulate cell growth and inhibit any uncontrollable cell growth in the healthy population; since p53 is inactivated in neurofibrosarcoma patients, they are much more susceptible to developing tumors.
(taking a sample of cells directly from the tumor itself). MRIs
, X-rays
, CT scans
, and bone scan
s can aid in locating a tumor and/or possible metastasis
.
Surgery is an option; the removal of the tumor along with surrounding tissue may be vital for the patient’s survival. For discrete, localized tumors, surgery is often followed by radiation
therapy of the excised area to reduce the chance of recurrence.
For patients suffering from neurofibrosarcomas in an extremity, if the tumor is vascularized (has its own blood supply) and has many nerves going through it and/or around it, amputation of the extremity may be necessary. Some surgeons argue that amputation should be the procedure of choice when possible, due to the increased chance of a better quality of life. Otherwise, surgeons may opt for a limb-saving treatment, by removing less of the surrounding tissue or part of the bone, which is replaced by a metal rod or grafts.
Radiation
will also be used in conjunction with surgery, especially if the limb was not amputated. Radiation is rarely used as a sole treatment.
In some instances, the oncologist may choose chemotherapy
drugs when treating a patient with neurofibrosarcoma, usually in conjunction with surgery. Patients taking chemotherapy must be prepared for the side effects that come with any other chemotherapy treatment, such as; hair loss, lethargy, weakness, etc.
It is a rare tumor type, with a relatively poor prognosis.
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
of the connective tissue
Connective tissue
"Connective tissue" is a fibrous tissue. It is one of the four traditional classes of tissues . Connective Tissue is found throughout the body.In fact the whole framework of the skeleton and the different specialized connective tissues from the crown of the head to the toes determine the form of...
surrounding nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
s. Given its origin and behavior it is classified as a sarcoma
Sarcoma
A sarcoma is a cancer that arises from transformed cells in one of a number of tissues that develop from embryonic mesoderm. Thus, sarcomas include tumors of bone, cartilage, fat, muscle, vascular, and hematopoietic tissues...
. About half the cases are diagnosed in people with neurofibromatosis
Neurofibromatosis
Neurofibromatosis is a genetically-inherited disorder in which the nerve tissue grows tumors that may be benign or may cause serious damage by compressing nerves and other tissues...
; the lifetime risk for an MPNST in patients with neurofibromatosis type 1 is 8-13%. MPNST with rhabdomyoblastomatous component are called Malignant triton tumor
Malignant triton tumor
Malignant triton tumor is a relatively rare, aggressive tumor made up of both malignant schwannoma cells and malignant rhabdomyoblasts...
s.
The first-line treatment is surgical resection with wide margins. Chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
(e.g. high-dose doxorubicin
Doxorubicin
Doxorubicin INN is a drug used in cancer chemotherapy. It is an anthracycline antibiotic, closely related to the natural product daunomycin, and like all anthracyclines, it works by intercalating DNA....
) and often radiotherapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
are done as adjuvant and/or neoadjuvant treatment.
Causes
Soft tissue sarcomas have been linked within families, so it is hypothesized that neurofibrosarcoma may be genetic, although researchers still do not know the exact cause of the disease. Evidence supporting this hypothesis includes loss of heterozygosity on the 17p chromosome. The p53P53
p53 , is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms, where it regulates the cell cycle and, thus, functions as a tumor suppressor that is involved in preventing cancer...
(a tumor suppressor gene in the normal population) genome on 17p in neurofibrosarcoma patients is mutated, increasing the probability of cancer. The normal p53 gene will regulate cell growth and inhibit any uncontrollable cell growth in the healthy population; since p53 is inactivated in neurofibrosarcoma patients, they are much more susceptible to developing tumors.
Symptoms
Symptoms may include:- Swelling in the extremities (arms or legs), also called peripheral edemaPeripheral edemaPeripheral edema is the swelling of tissues, usually in the lower limbs, due to the accumulation of fluids.The condition is commonly associated with aging, but can be caused by many other conditions, including congestive heart failure, trauma, alcoholism, altitude sickness, pregnancy,...
; the swelling often is painless. - Difficulty in moving the extremity that has the tumor, including a limp.
- Soreness localized to the area of the tumor or in the extremity.
Diagnosis
The most conclusive test for a patient with a potential neurofibrosarcoma is a tumor biopsyBiopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
(taking a sample of cells directly from the tumor itself). MRIs
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
, X-rays
Radiology
Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...
, CT scans
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
, and bone scan
Bone scan
A bone scan or bone scintigraphy is a nuclear scanning test to find certain abnormalities in bone which are triggering the bone's attempts to heal. It is primarily used to help diagnose a number of conditions relating to bones, including: cancer of the bone or cancers that have spread to the bone,...
s can aid in locating a tumor and/or possible metastasis
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
.
Treatment
Treatment for neurofibrosarcoma is similar to that of other cancers.Surgery is an option; the removal of the tumor along with surrounding tissue may be vital for the patient’s survival. For discrete, localized tumors, surgery is often followed by radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
therapy of the excised area to reduce the chance of recurrence.
For patients suffering from neurofibrosarcomas in an extremity, if the tumor is vascularized (has its own blood supply) and has many nerves going through it and/or around it, amputation of the extremity may be necessary. Some surgeons argue that amputation should be the procedure of choice when possible, due to the increased chance of a better quality of life. Otherwise, surgeons may opt for a limb-saving treatment, by removing less of the surrounding tissue or part of the bone, which is replaced by a metal rod or grafts.
Radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
will also be used in conjunction with surgery, especially if the limb was not amputated. Radiation is rarely used as a sole treatment.
In some instances, the oncologist may choose chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
drugs when treating a patient with neurofibrosarcoma, usually in conjunction with surgery. Patients taking chemotherapy must be prepared for the side effects that come with any other chemotherapy treatment, such as; hair loss, lethargy, weakness, etc.
Prognosis
Patient response to treatment will vary based on age, health, and the tolerance to medications and therapies. Also, the extent of the disease i.e. metastasis and size/location of the tumor, have an effect on the patient’s recoveryIt is a rare tumor type, with a relatively poor prognosis.
See also
- Keratinizing metaplasiaKeratinizing metaplasiaKeratinizing metaplasia is a condition affecting the epithelial surfaces of the body. It is caused by a dietary deficiency of vitamin A, a fat-soluble vitamin that is most often found in fats, milk, and some leafy vegetables....
- List of cutaneous conditions
- 50/50 (2011 film)
External links
- Malignant Peripheral Nerve Sheath Tumors (MPNST) by David S. Geller, MD and Mark Gebhardt, MD