A moderately firm, benign, encapsulated tumor resulting from proliferation of SCHWANN CELLS and FIBROBLASTS that includes portions of nerve fibers. The tumors usually develop along peripheral or cranial nerves and are a central feature of NEUROFIBROMATOSIS 1, where they may occur intracranially or involve spinal roots. Pathologic features include fusiform enlargement of the involved nerve. Microscopic examination reveals a disorganized and loose cellular pattern with elongated nuclei intermixed with fibrous strands. (From Adams et al., Principles of Neurology, 6th ed, p1016)
A type of neurofibroma manifesting as a diffuse overgrowth of subcutaneous tissue, usually involving the face, scalp, neck, and chest but occasionally occurring in the abdomen or pelvis. The tumors tend to progress, and may extend along nerve roots to eventually involve the spinal roots and spinal cord. This process is almost always a manifestation of NEUROFIBROMATOSIS 1. (From Adams et al., Principles of Neurology, 6th ed, p1016; J Pediatr 1997 Nov;131(5):678-82)
An autosomal dominant inherited disorder (with a high frequency of spontaneous mutations) that features developmental changes in the nervous system, muscles, bones, and skin, most notably in tissue derived from the embryonic NEURAL CREST. Multiple hyperpigmented skin lesions and subcutaneous tumors are the hallmark of this disease. Peripheral and central nervous system neoplasms occur frequently, especially OPTIC NERVE GLIOMA and NEUROFIBROSARCOMA. NF1 is caused by mutations which inactivate the NF1 gene (GENES, NEUROFIBROMATOSIS 1) on chromosome 17q. The incidence of learning disabilities is also elevated in this condition. (From Adams et al., Principles of Neurology, 6th ed, pp1014-18) There is overlap of clinical features with NOONAN SYNDROME in a syndrome called neurofibromatosis-Noonan syndrome. Both the PTPN11 and NF1 gene products are involved in the SIGNAL TRANSDUCTION pathway of Ras (RAS PROTEINS).
A protein found most abundantly in the nervous system. Defects or deficiencies in this protein are associated with NEUROFIBROMATOSIS 1, Watson syndrome, and LEOPARD syndrome. Mutations in the gene (GENE, NEUROFIBROMATOSIS 1) affect two known functions: regulation of ras-GTPase and tumor suppression.
A malignant tumor that arises from small cutaneous nerves, is locally aggressive, and has a potential for metastasis. Characteristic histopathologic features include proliferating atypical spindle cells with slender wavy and pointed nuclei, hypocellular areas, and areas featuring organized whorls of fibroblastic proliferation. The most common primary sites are the extremities, retroperitoneum, and trunk. These tumors tend to present in childhood, often in association with NEUROFIBROMATOSIS 1. (From DeVita et al., Cancer: Principles & Practice of Oncology, 5th ed, p1662; Mayo Clin Proc 1990 Feb;65(2):164-72)
Neoplasms which arise from nerve sheaths formed by SCHWANN CELLS in the PERIPHERAL NERVOUS SYSTEM or by OLIGODENDROCYTES in the CENTRAL NERVOUS SYSTEM. Malignant peripheral nerve sheath tumors, NEUROFIBROMA, and NEURILEMMOMA are relatively common tumors in this category.
A group of disorders characterized by an autosomal dominant pattern of inheritance with high rates of spontaneous mutation and multiple neurofibromas or neurilemmomas. NEUROFIBROMATOSIS 1 (generalized neurofibromatosis) accounts for approximately 95% of cases, although multiple additional subtypes (e.g., NEUROFIBROMATOSIS 2, neurofibromatosis 3, etc.) have been described. (From Neurochirurgie 1998 Nov;44(4):267-72)
Neoplasms which arise from peripheral nerve tissue. This includes NEUROFIBROMAS; SCHWANNOMAS; GRANULAR CELL TUMORS; and malignant peripheral NERVE SHEATH NEOPLASMS. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp1750-1)
Tumor suppressor genes located on the long arm of human chromosome 17 in the region 17q11.2. Mutation of these genes is thought to cause NEUROFIBROMATOSIS 1, Watson syndrome, and LEOPARD syndrome.
Neuroglial cells of the peripheral nervous system which form the insulating myelin sheaths of peripheral axons.
Light brown pigmented macules associated with NEUROFIBROMATOSIS and Albright's syndrome (see FIBROUS DYSPLASIA, POLYOSTOTIC).
A neoplasm that arises from SCHWANN CELLS of the cranial, peripheral, and autonomic nerves. Clinically, these tumors may present as a cranial neuropathy, abdominal or soft tissue mass, intracranial lesion, or with spinal cord compression. Histologically, these tumors are encapsulated, highly vascular, and composed of a homogenous pattern of biphasic fusiform-shaped cells that may have a palisaded appearance. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp964-5)
A tumor made up of nerve cells and nerve fibers. (Dorland, 27th ed)
X-ray visualization of the spinal cord following injection of contrast medium into the spinal arachnoid space.
Diseases of the tenth cranial nerve, including brain stem lesions involving its nuclei (solitary, ambiguus, and dorsal motor), nerve fascicles, and intracranial and extracranial course. Clinical manifestations may include dysphagia, vocal cord weakness, and alterations of parasympathetic tone in the thorax and abdomen.
Tumors or cancer of the MANDIBLE.
'Gingival neoplasms' are abnormal, uncontrolled growths of tissue originating from the gingiva, which can be benign (non-cancerous) or malignant (cancerous), often manifesting as swellings, ulcerations, or masses within the oral cavity.
The outer covering of the calvaria. It is composed of several layers: SKIN; subcutaneous connective tissue; the occipitofrontal muscle which includes the tendinous galea aponeurotica; loose connective tissue; and the pericranium (the PERIOSTEUM of the SKULL).
Benign and malignant neoplasms which occur within the substance of the spinal cord (intramedullary neoplasms) or in the space between the dura and spinal cord (intradural extramedullary neoplasms). The majority of intramedullary spinal tumors are primary CNS neoplasms including ASTROCYTOMA; EPENDYMOMA; and LIPOMA. Intramedullary neoplasms are often associated with SYRINGOMYELIA. The most frequent histologic types of intradural-extramedullary tumors are MENINGIOMA and NEUROFIBROMA.
A benign tumor composed of fat cells (ADIPOCYTES). It can be surrounded by a thin layer of connective tissue (encapsulated), or diffuse without the capsule.
A family of highly acidic calcium-binding proteins found in large concentration in the brain and believed to be glial in origin. They are also found in other organs in the body. They have in common the EF-hand motif (EF HAND MOTIFS) found on a number of calcium binding proteins. The name of this family derives from the property of being soluble in a 100% saturated ammonium sulfate solution.
An autosomal dominant disorder characterized by a high incidence of bilateral acoustic neuromas as well as schwannomas (NEURILEMMOMA) of other cranial and peripheral nerves, and other benign intracranial tumors including meningiomas, ependymomas, spinal neurofibromas, and gliomas. The disease has been linked to mutations of the NF2 gene (GENES, NEUROFIBROMATOSIS 2) on chromosome 22 (22q12) and usually presents clinically in the first or second decade of life.
Neoplasms of whatever cell type or origin, occurring in the extraskeletal connective tissue framework of the body including the organs of locomotion and their various component structures, such as nerves, blood vessels, lymphatics, etc.

Color Doppler sonography of focal lesions of the skin and subcutaneous tissue. (1/182)

We evaluated with color Doppler sonography 71 visible and palpable nodules of the skin and subcutaneous tissue from 51 patients. The nodules were classified as avascular (type I), hypovascular with a single vascular pole (type II), hypervascular with multiple peripheral poles (type III), and hypervascular with internal vessels (type IV). Of the 32 malignant nodules, 9% showed a type I pattern, 50% had a type III pattern, and 41% had a type IV pattern; of the 39 benign nodules, 86% showed a type I pattern and 14% had a type II pattern. The sensitivity and specificity of hypervascularity in malignant lesions were 90% and 100%, respectively, whereas the sensitivity and specificity of hypovascularity in benign lesions were 100% and 90%, respectively. The authors conclude that color Doppler sonography is able to increase the specificity of ultrasonography in the evaluation of nodular lesions of the skin.  (+info)

Extreme lateral transcondylar approach to the skull base. (2/182)

In this study, the authors present their experience of using extreme later transcondylar approach (ELTC) for treating 7 patients with lesions in the anterolateral foramen magnum, upper cervical spine and cerebellopontine angle reaching upto jugular foramen. The tumours included meningiomas, neurofibromas (2 cases each), chondrosarcoma, epidermoid and aneurysmal bone cyst (one case each). The approach was used alone, in combination with retrolabyrinthine presigmoid approach in a patient with lower cranial nerve neurofibroma extending extracranially through the jugular foramen, or in combination with partial C1-C3 laminectomy in two patients with meningiomas situated anterolateral to the cord from the foramen magnum to C3. In two patients with extradural vertebral artery (VA) entrapment by a chondrosarcoma and aneurysmal bone cyst respectively, the vertebral artery was ligated distal to the tumour. The tumours were totally excised in five cases and partially in two. There was no preoperative mortality. The major complications included cerebrospinal fluid leak from the wound (3 cases) and increase in lower cranial nerve paresis (2 cases). At follow up, ranging from 6 months to 2 years, 5 patients showed no tumour recurrence. There was improvement in neurological status. One patient, with a partially excised aneurysmal bone cyst, showed no added deficits or increase in the tumour size. However, there was a massive regrowth in the patient with chondrosarcoma after 6 months. This technique provided a wide surgical exposure with direct visualization of the tumour-anterior cord interface, early proximal control of the VA and preservation of lower cranial nerves.  (+info)

Deletions of the INK4A gene occur in malignant peripheral nerve sheath tumors but not in neurofibromas. (3/182)

The INK4A gene, a candidate tumor suppressor gene located on chromosome 9p21, encodes two protein products, p16 and p19(ARF). p16 is a negative cell cycle regulator capable of arresting cells in the G1 phase by inhibiting cyclin-dependent kinases 4 (Cdk4) and 6 (Cdk6), thus preventing pRB phosphorylation. p19(ARF) prevents Mdm2-mediated neutralization of p53. Loss of INK4A is a frequent molecular alteration involved in the genesis of several neoplasms, including tumors of neuroectodermal origin. This study investigated the frequency of INK4A gene alterations in a series of malignant peripheral nerve sheath tumors (MPNSTs) and neurofibromas (NFs). INK4A gene and the p19(ARF)-specific exon 1beta were studied in 11 MPNST samples from 8 patients and 7 neurofibromas. Presence of INK4A deletions was assessed by Southern blotting hybridization and by a multiplex polymerase chain reaction (mPCR). INK4A point mutations were examined by single-strand conformation polymorphism (SSCP) and sequencing. The p16 promoter methylation status was determined by PCR amplification of bisulfite-treated DNA. Homozygous deletions of exon 2, thus affecting both p16 and p19(ARF), were identified in MPNSTs from 4 of 8 patients. Deletions, mutations, or silencing by methylation were not identified in the neurofibromas analyzed. Based on our results, we conclude that INK4A deletions are frequent events in MPNSTs and may participate in tumor progression. Silencing of p16 by methylation, which occurs often in several tumor types, is uncommon in MPNSTs.  (+info)

Malignant transformation of neurofibromas in neurofibromatosis 1 is associated with CDKN2A/p16 inactivation. (4/182)

Patients with neurofibromatosis 1 (NF1) are predisposed to develop multiple neurofibromas (NFs) and are at risk for transformation of NFs to malignant peripheral nerve sheath tumors (MPNSTs). Little is known, however, about the biological events involved in the malignant transformation of NFs. We examined the CDKN2A/p16 gene and p16 protein in NFs and MPNSTs from patients with NF1. On immunohistochemical analysis, all NFs expressed p16 protein. The MPNSTs, however, were essentially immunonegative for p16, with striking transitions in cases that contained both benign and malignant elements. None of the benign tumors had CDKN2A/p16 deletions, whereas three of six MPNSTs appeared to have homozygous CDKN2A/p16 deletions. Methylation analysis and mutation analysis of CDKN2A/p16 in MPNSTs did not reveal any abnormalities. These results show that malignant transformation of NF is associated with loss of p16 expression, which is often secondary to homozygous deletion of the CDKN2A/p16 gene. The findings suggest that CDKN2A/p16 inactivation occurs during the malignant transformation of NFs in NF1 patients and raises the possibility that p16 immunohistochemistry may provide ancillary information in the distinction of NF from MPNST.  (+info)

Expression of p27(kip) and other cell cycle regulators in malignant peripheral nerve sheath tumors and neurofibromas: the emerging role of p27(kip) in malignant transformation of neurofibromas. (5/182)

There is little information regarding the status of cell cycle regulators in malignant peripheral nerve sheath tumors (MPNSTs) and neurofibromas (NFs). In this study, we investigated patterns of expression of p53 and pRB, cyclin-dependent kinase inhibitors (CKIs) p21 and p27, as well as cyclins D1 and E, in a cohort of 35 well-characterized MPNSTs and 16 NFs. These phenotypes were correlated with proliferative index, as assessed by Ki-67, as well as clinicopathological parameters of poor outcome. p53 nuclear overexpression was found in 10 of 35 (29%) MPNSTs, and it was lacking in NFs (P = 0.02). There were no differences in the patterns of expression of pRB, cyclin D1, and p21 between MPNSTs and NFs. However, p27 nuclear expression was present in most NFs, but it was absent in the majority of MPNSTs, which displayed cytoplasmic staining (P < 0.001). Nuclear cyclin E expression was more pronounced in MPNSTs than in NFs. We observed inverse patterns of expression for nuclear p27 and nuclear cyclin E expression. The staining profiles of cytoplasmic p27 and nuclear cyclin E expression were found to be statistically associated (P = 0.01). High Ki-67 expression was found in 20 of 34 (59%) MPNSTs but was absent in NFs (P < 0.001). Furthermore, detection of cytoplasmic p27 expression was found to be a prognostic factor for poor survival in MPNSTs (P = 0.03, relative risk = 2.4).  (+info)

Evaluation of (18)fluorodeoxyglucose positron emission tomography ((18)FDG PET) in the detection of malignant peripheral nerve sheath tumours arising from within plexiform neurofibromas in neurofibromatosis 1. (6/182)

OBJECTIVES: The ability of (18)fluorodeoxyglucose positron emission tomography ((18)FDG PET) to detect malignant change in plexiform neurofibromas from patients with neurofibromatosis 1 (NF1) was evaluated. METHODS: Eighteen NF1 patients who presented with pain, increase in size, or neurological deficit associated with a plexiform neurofibroma were assessed. Magnetic resonance imaging determined the site and extent of the lesion. Qualitative(18)FDG PET was performed and the standard uptake value (SUV) measured the regional glucose metabolism. Histological confirmation of the diagnosis was obtained in 10 patients. RESULTS: Twenty three plexiform neurofibromas were detected in 18 patients. Seven malignant peripheral nerve sheath tumours, four high grade and three low grade tumours, occurred in five patients. In one patient the clinical and radiological characteristics of the tumour suggested malignancy, but histology was inconclusive. Fifteen benign plexiform neurofibromas were identified in 12 patients and these findings were confirmed histologically in five lesions from four patients. Ten plexiform neurofibromas occurring in eight patients were considered benign on(18)FDG PET and the patients did not undergo surgery. They remained stable or their symptoms improved on clinical follow up (median 9 months). The results of qualitative (18)FDG PET were interpreted as indicating that 13 plexiform neurofibromas were benign and 10 were malignant. No malignant tumours were classified as benign, but two benign tumours were reported as malignant. The SUV was calculated for 20 tumours and was significantly higher in five malignant tumours 5.4 (SD 2.4), than in 15 benign tumours 1.54 (SD 0.7), p=0.002. There was an overlap between benign and malignant tumours in the SUV range 2.7-3.3. CONCLUSIONS: (18)FDG PET is helpful in determining malignant change in plexiform neurofibromas in NF1. Increased separation between benign and malignant lesions could be obtained by calculating the SUV at about 200 minutes after injection of (18)FDG, when the peak activity concentration is obtained in malignant tumours.  (+info)

Melanotic neurofibroma in a steer. (7/182)

A melanotic neurofibroma in a steer was investigated histologically, immunohistochemically and ultrastructurally. A very large tumor mass was located in the region of the head and right cheek. The tumor tissue consisted of an admixture of cells resembling Schwann cells and spindle-shaped cells, and they frequently contained melanin granules. Neoplastic Schwann cells were positive for S100 protein, with variation in intensity of staining, but most spindled cells were S100 negative. The tumor cells displayed ultrastructural features similar to those of Schwann cells or perineurial cells. The presence of melanosomes in varying stages of melanization in both cell types suggests that they have a common origin. This is a tumor of neural crest origin showing schwannian and perineurial differentiation, with ectopic production of melanin granules.  (+info)

Genetic and cellular defects contributing to benign tumor formation in neurofibromatosis type 1. (8/182)

Neurofibromatosis type 1 (NF1) is a common inherited cancer predisposition syndrome. The NF1 gene product, neurofibromin, is hypothesized to function as a tumor suppressor and nearly all NF1 patients develop benign peripheral nerve tumors. These neurofibromas presumably arise from NF1 inactivation in S100(+)Schwann cells, but there is no formal proof for this mechanism. We demonstrate that fibro-blasts isolated from neurofibromas carried at least one normal NF1 allele and expressed both NF1 mRNA and protein, whereas the S100(+)cells typically lacked the NF1 transcript. Our findings further indicate that additional molecular events aside from NF1 inactivation in Schwann cells and/or other neural crest derivatives contribute to neurofibroma formation.  (+info)

A neurofibroma is a benign (non-cancerous) tumor that develops from the nerve sheath, which is the protective covering around nerves. These tumors can grow anywhere on the body and can be found under the skin or deep inside the body. Neurofibromas can vary in size, and they may cause symptoms such as pain, numbness, or tingling if they press on nearby nerves.

Neurofibromas are a common feature of neurofibromatosis type 1 (NF1), a genetic disorder that affects approximately 1 in every 3,000 people worldwide. NF1 is characterized by the development of multiple neurofibromas and other tumors, as well as skin changes such as café-au-lait spots and freckling.

It's important to note that while most neurofibromas are benign, they can rarely undergo malignant transformation and become cancerous. If you have a neurofibroma or are concerned about your risk of developing one, it's important to seek medical advice from a healthcare professional who is familiar with this condition.

A plexiform neurofibroma is a type of neurofibroma, which is a benign tumor that develops from the nerve sheath. In a plexiform neurofibroma, the tumor grows along the nerves and can involve multiple fascicles, leading to a large, diffuse mass. These tumors can occur anywhere in the body but are most commonly found in the head, neck, and trunk.

Plexiform neurofibromas can be associated with neurofibromatosis type 1 (NF1), a genetic disorder that affects approximately 1 in every 3,000 people worldwide. In individuals with NF1, plexiform neurofibromas can cause significant morbidity, including disfigurement, pain, and functional impairment. Additionally, there is a small risk of malignant transformation into a type of cancer called malignant peripheral nerve sheath tumor (MPNST).

The diagnosis of plexiform neurofibromas is typically made based on clinical examination, medical history, and imaging studies such as MRI. A biopsy may be necessary to confirm the diagnosis. Treatment options for plexiform neurofibromas include surgery, radiation therapy, and medication. The choice of treatment depends on several factors, including the size and location of the tumor, the presence of symptoms, and the risk of malignant transformation.

Neurofibromatosis 1 (NF1) is a genetic disorder that affects the development and growth of nerve tissue. It's also known as von Recklinghausen disease. NF1 is characterized by the growth of non-cancerous tumors on the nerves, as well as skin and bone abnormalities.

The symptoms of Neurofibromatosis 1 can vary widely, even among members of the same family. Some common features include:

* Multiple café au lait spots (flat, light brown patches on the skin)
* Freckles in the underarms and groin area
* Benign growths on or under the skin called neurofibromas
* Larger, more complex tumors called plexiform neurofibromas
* Optic gliomas (tumors that form on the optic nerve)
* Distinctive bone abnormalities, such as a curved spine (scoliosis) or an enlarged head (macrocephaly)
* Learning disabilities and behavioral problems

Neurofibromatosis 1 is caused by mutations in the NF1 gene, which provides instructions for making a protein called neurofibromin. This protein helps regulate cell growth and division. When the NF1 gene is mutated, the production of neurofibromin is reduced or absent, leading to uncontrolled cell growth and the development of tumors.

NF1 is an autosomal dominant disorder, which means that a person has a 50% chance of inheriting the mutated gene from an affected parent. However, about half of all cases are the result of new mutations in the NF1 gene, and occur in people with no family history of the disorder.

There is currently no cure for Neurofibromatosis 1, but treatments are available to manage the symptoms and complications of the disease. These may include medications to control pain or reduce the size of tumors, surgery to remove tumors or correct bone abnormalities, and physical therapy to improve mobility and strength. Regular monitoring by a healthcare team experienced in treating Neurofibromatosis 1 is also important to detect any changes in the condition and provide appropriate care.

Neurofibromin 1 is a protein that is encoded by the NF1 gene in humans. Neurofibromin 1 acts as a tumor suppressor, helping to regulate cell growth and division. It plays an important role in the nervous system, where it helps to control the development and function of nerve cells. Mutations in the NF1 gene can lead to neurofibromatosis type 1 (NF1), a genetic disorder characterized by the growth of non-cancerous tumors on the nerves (neurofibromas) and other symptoms.

Neurofibrosarcoma is a rare type of soft tissue sarcoma, which is a cancer that develops in the soft tissues of the body such as fat, muscle, tendons, blood vessels, and nerves. Neurofibrosarcoma specifically arises from the nerve sheath cells, also known as the Schwann cells, that cover and protect the peripheral nerves.

This type of cancer typically forms a painless mass or tumor in the affected area, which can grow and invade nearby tissues and organs over time. Neurofibrosarcoma can occur anywhere in the body but is most commonly found in the arms, legs, trunk, or head and neck region.

Neurofibrosarcoma can be classified into two main types: conventional and malignant peripheral nerve sheath tumor (MPNST). Conventional neurofibrosarcoma is more common and tends to occur in older adults, while MPNST is a more aggressive form that is associated with genetic disorders such as neurofibromatosis type 1.

Treatment for neurofibrosarcoma typically involves surgical removal of the tumor, along with radiation therapy and/or chemotherapy to help prevent recurrence and spread of the cancer. The prognosis for neurofibrosarcoma varies depending on several factors, including the size and location of the tumor, the patient's age and overall health, and the stage of the disease at diagnosis.

Nerve sheath neoplasms are a group of tumors that arise from the cells surrounding and supporting the nerves. These tumors can be benign or malignant and include schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors (MPNSTs). Schwannomas develop from the Schwann cells that produce the myelin sheath of the nerve, while neurofibromas arise from the nerve's supporting cells called fibroblasts. MPNSTs are cancerous tumors that can grow rapidly and invade surrounding tissues. Nerve sheath neoplasms can cause various symptoms depending on their location and size, including pain, numbness, weakness, or paralysis in the affected area.

Neurofibromatoses are a group of genetic disorders that primarily affect the nervous system. The term "neurofibromatosis" is often used to refer to two specific conditions: neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2). These conditions are characterized by the growth of tumors on the nerves, called neurofibromas.

Neurofibromatosis type 1 (NF1): This is the most common form of neurofibromatosis, affecting about 1 in every 3,000 people worldwide. NF1 is caused by mutations in the NF1 gene and is characterized by the development of benign tumors on the nerves called neurofibromas. These tumors can develop anywhere on the body, including the skin, spinal cord, and brain. Other common features of NF1 include:

* Freckles in the underarms and groin area
* Lisch nodules (small, noncancerous growths) on the iris of the eye
* Bone abnormalities, such as scoliosis or bowing of the legs
* Learning disabilities or cognitive impairment

Neurofibromatosis type 2 (NF2): This form of neurofibromatosis is much rarer than NF1, affecting about 1 in every 30,000 people worldwide. NF2 is caused by mutations in the NF2 gene and is characterized by the development of benign tumors on the nerves that transmit sound from the inner ear to the brain (acoustic neuromas). These tumors can cause hearing loss, ringing in the ears, and balance problems. Other common features of NF2 include:

* Multiple schwannomas (tumors that develop on the protective covering of the nerves)
* Meningiomas (tumors that develop in the membranes surrounding the brain and spinal cord)
* Skin tumors called neurofibromas, although these are less common than in NF1

It is important to note that while neurofibromatoses can cause a range of symptoms and complications, most people with these conditions have a normal lifespan. With proper medical care and monitoring, it is possible to manage the symptoms and reduce the risk of complications.

Peripheral nervous system (PNS) neoplasms refer to tumors that originate in the peripheral nerves, which are the nerves outside the brain and spinal cord. These tumors can be benign or malignant (cancerous). Benign tumors, such as schwannomas and neurofibromas, grow slowly and do not spread to other parts of the body. Malignant tumors, such as malignant peripheral nerve sheath tumors (MPNSTs), can invade nearby tissues and may metastasize (spread) to other organs.

PNS neoplasms can cause various symptoms depending on their location and size. Common symptoms include pain, weakness, numbness, or tingling in the affected area. In some cases, PNS neoplasms may not cause any symptoms until they become quite large. Treatment options for PNS neoplasms depend on several factors, including the type, size, and location of the tumor, as well as the patient's overall health. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

Neurofibromatosis 1 (NF1) is a genetic disorder caused by mutations in the NF1 gene, which is located on chromosome 17 and encodes the protein neurofibromin. Neurofibromin is a tumor suppressor protein that regulates cell growth and differentiation.

The NF1 gene mutation leads to the development of benign (non-cancerous) tumors on nerves and skin, called neurofibromas, as well as other clinical features such as café-au-lait spots (light brown patches on the skin), freckling in the axillary or inguinal regions, Lisch nodules (harmless growths on the iris of the eye), and skeletal abnormalities.

Neurofibromatosis 1 is an autosomal dominant disorder, which means that a person has a 50% chance of inheriting the mutated gene from an affected parent. However, up to 50% of cases result from new mutations in the NF1 gene and occur in people with no family history of the condition.

The clinical manifestations of Neurofibromatosis 1 can vary widely among individuals, even within the same family. The diagnosis is typically made based on clinical criteria established by the National Institutes of Health (NIH). Treatment is generally focused on managing symptoms and addressing complications as they arise, although surgery may be necessary to remove large or symptomatic tumors.

Schwann cells, also known as neurolemmocytes, are a type of glial cell that form the myelin sheath around peripheral nervous system (PNS) axons, allowing for the rapid and efficient transmission of nerve impulses. These cells play a crucial role in the maintenance and function of the PNS.

Schwann cells originate from the neural crest during embryonic development and migrate to the developing nerves. They wrap around the axons in a spiral fashion, forming multiple layers of myelin, which insulates the nerve fibers and increases the speed of electrical impulse transmission. Each Schwann cell is responsible for myelinating a single segment of an axon, with the gaps between these segments called nodes of Ranvier.

Schwann cells also provide structural support to the neurons and contribute to the regeneration of injured peripheral nerves by helping to guide the regrowth of axons to their targets. Additionally, Schwann cells can participate in immune responses within the PNS, such as releasing cytokines and chemokines to recruit immune cells during injury or infection.

Café-au-lait spots are light to dark brown, flat patches on the skin that are benign and usually harmless. The term "café-au-lait" means "coffee with milk," which describes the color of these spots. They can vary in size from a few millimeters to several centimeters in diameter and can appear anywhere on the body, although they are most commonly found on the trunk and buttocks.

While café-au-lait spots are common and can occur in up to 20% of the general population, having multiple (more than six) such spots, especially if they are large or present at birth, may be a sign of an underlying medical condition, such as neurofibromatosis type 1 (NF1), a genetic disorder that affects the growth and development of nerve tissue.

Therefore, it is essential to monitor café-au-lait spots and report any changes or concerns to a healthcare provider.

A neurilemmoma, also known as schwannoma or peripheral nerve sheath tumor, is a benign, slow-growing tumor that arises from the Schwann cells, which produce the myelin sheath that surrounds and insulates peripheral nerves. These tumors can occur anywhere along the course of a peripheral nerve, but they most commonly affect the acoustic nerve (vestibulocochlear nerve), leading to a type of tumor called vestibular schwannoma or acoustic neuroma. Neurilemmomas are typically encapsulated and do not invade the surrounding tissue, although larger ones may cause pressure-related symptoms due to compression of nearby structures. Rarely, these tumors can undergo malignant transformation, leading to a condition called malignant peripheral nerve sheath tumor or neurofibrosarcoma.

A neuroma is not a specific type of tumor, but rather refers to a benign (non-cancerous) growth or swelling of nerve tissue. The most common type of neuroma is called a Morton's neuroma, which typically occurs between the third and fourth toes in the foot. It develops as a result of chronic irritation, compression, or trauma to the nerves leading to the toes, causing them to thicken and enlarge.

Morton's neuroma can cause symptoms such as pain, numbness, tingling, or burning sensations in the affected area. Treatment options for Morton's neuroma may include rest, ice, orthotics, physical therapy, medication, or in some cases, surgery. It is essential to consult a healthcare professional if you suspect you have a neuroma or are experiencing related symptoms.

Myelography is a medical imaging technique used to examine the spinal cord and surrounding structures, such as the spinal nerves, intervertebral discs, and the spinal column. This procedure involves the injection of a contrast dye into the subarachnoid space, which is the area surrounding the spinal cord filled with cerebrospinal fluid (CSF). The dye outlines the spinal structures, making them visible on X-ray or CT scan images.

The primary purpose of myelography is to diagnose various spinal conditions, including herniated discs, spinal stenosis, tumors, infection, and traumatic injuries. It can help identify any compression or irritation of the spinal cord or nerves that may be causing pain, numbness, weakness, or other neurological symptoms.

The procedure typically requires the patient to lie flat on their stomach or side while the radiologist inserts a thin needle into the subarachnoid space, usually at the lower lumbar level. Once the contrast dye is injected, the patient will be repositioned for various X-ray views or undergo a CT scan to capture detailed images of the spine. After the procedure, patients may experience headaches, nausea, or discomfort at the injection site, but these symptoms usually resolve within a few days.

Vagus nerve diseases, also known as vagus nerve disorders, refer to conditions that affect the functioning of the vagus nerve. The vagus nerve is the tenth cranial nerve and extends from the brainstem to the abdomen, playing a crucial role in regulating various automatic functions of the body such as heart rate, digestion, respiratory rate, and sweating.

Diseases of the vagus nerve can result from various causes, including inflammation, infection, trauma, compression, or degeneration. Some common vagus nerve disorders include:

1. Vagus nerve dysfunction: This is a general term used to describe any abnormality in the functioning of the vagus nerve. Symptoms may vary depending on the specific functions affected but can include difficulty swallowing, hoarseness, voice changes, and abnormal heart rate or blood pressure.
2. Vagus nerve neuropathy: This is a condition that results from damage to the vagus nerve fibers. It can cause symptoms such as difficulty swallowing, voice changes, and abnormal digestive function.
3. Gastroparesis: This is a condition in which the stomach muscles fail to contract properly, leading to delayed gastric emptying. Vagus nerve dysfunction is a common cause of gastroparesis.
4. Orthostatic hypotension: This is a condition characterized by a drop in blood pressure when standing up from a sitting or lying down position. Vagus nerve dysfunction can contribute to this condition by causing an abnormal response in the heart rate and blood vessels.
5. Inflammatory disorders: Certain inflammatory conditions such as rheumatoid arthritis, lupus, and sarcoidosis can affect the vagus nerve and cause various symptoms.

Treatment for vagus nerve diseases depends on the underlying cause and may include medications, surgery, or lifestyle changes.

Mandibular neoplasms refer to abnormal growths or tumors that develop in the mandible, which is the lower jawbone. These growths can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms are typically slow-growing and rarely spread to other parts of the body, while malignant neoplasms can invade surrounding tissues and may metastasize (spread) to distant sites.

Mandibular neoplasms can have various causes, including genetic mutations, exposure to certain chemicals or radiation, and infection with certain viruses. The symptoms of mandibular neoplasms may include swelling or pain in the jaw, difficulty chewing or speaking, numbness in the lower lip or chin, loose teeth, and/or a lump or mass in the mouth or neck.

The diagnosis of mandibular neoplasms typically involves a thorough clinical examination, imaging studies such as X-rays, CT scans, or MRI scans, and sometimes a biopsy to confirm the type and extent of the tumor. Treatment options depend on the type, stage, and location of the neoplasm, and may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence or metastasis.

Gingival neoplasms refer to abnormal growths or tumors that occur in the gingiva, which are the part of the gums that surround the teeth. These growths can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms include conditions such as fibromas, papillomas, and hemangiomas, while malignant neoplasms are typically squamous cell carcinomas.

Gingival neoplasms can present with a variety of symptoms, including swelling, bleeding, pain, and loose teeth. They may also cause difficulty with chewing, speaking, or swallowing. The exact cause of these neoplasms is not always known, but risk factors include tobacco use, alcohol consumption, poor oral hygiene, and certain viral infections.

Diagnosis of gingival neoplasms typically involves a thorough clinical examination, including a dental exam and biopsy. Treatment options depend on the type and stage of the neoplasm, but may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. Regular dental check-ups and good oral hygiene practices can help to detect gingival neoplasms at an early stage and improve treatment outcomes.

The scalp is the anatomical region located at the upper part of the human head, covering the skull except for the face and the ears. It is made up of several layers: the skin, the connective tissue, the galea aponeurotica (a strong, flat, tendinous sheet), loose areolar tissue, and the periosteum (the highly vascularized innermost layer that attaches directly to the skull bones). The scalp has a rich blood supply and is home to numerous sensory receptors, including those for touch, pain, and temperature. It also contains hair follicles, sebaceous glands, and sweat glands.

Spinal cord neoplasms refer to abnormal growths or tumors within the spinal cord. These can be benign (non-cancerous) or malignant (cancerous). They originate from the cells within the spinal cord itself (primary tumors), or they may spread to the spinal cord from other parts of the body (metastatic tumors). Spinal cord neoplasms can cause various symptoms depending on their location and size, including back pain, neurological deficits, and even paralysis. Treatment options include surgery, radiation therapy, and chemotherapy.

A lipoma is a common, benign (non-cancerous) soft tissue growth. It is composed of adipose or fatty tissue and typically found just beneath the skin, but they can also occur deeper within the body. Lipomas are usually round, moveable, and painless, although they may cause discomfort if they grow large enough to put pressure on nearby nerves or if they're located in a sensitive area. They generally grow slowly over time. Surgical removal is an option if the lipoma becomes bothersome or grows significantly in size. It's important to note that while lipomas are typically harmless, any new lumps or bumps should be evaluated by a healthcare professional to confirm the diagnosis and rule out other more serious conditions.

S100 proteins are a family of calcium-binding proteins that are involved in the regulation of various cellular processes, including cell growth and differentiation, intracellular signaling, and inflammation. They are found in high concentrations in certain types of cells, such as nerve cells (neurons), glial cells (supporting cells in the nervous system), and skin cells (keratinocytes).

The S100 protein family consists of more than 20 members, which are divided into several subfamilies based on their structural similarities. Some of the well-known members of this family include S100A1, S100B, S100 calcium-binding protein A8 (S100A8), and S100 calcium-binding protein A9 (S100A9).

Abnormal expression or regulation of S100 proteins has been implicated in various pathological conditions, such as neurodegenerative diseases, cancer, and inflammatory disorders. For example, increased levels of S100B have been found in the brains of patients with Alzheimer's disease, while overexpression of S100A8 and S100A9 has been associated with the development and progression of certain types of cancer.

Therefore, understanding the functions and regulation of S100 proteins is important for developing new diagnostic and therapeutic strategies for various diseases.

Neurofibromatosis 2 (NF2) is a genetic disorder characterized by the development of non-cancerous tumors in the nervous system, particularly on the nerves related to hearing and balance. It's also known as central neurofibromatosis or bilateral acoustic neuroma syndrome.

The primary feature of NF2 is the growth of schwannomas, which are tumors that develop from the cells surrounding nerve fibers. These typically grow on the vestibular nerve, leading to hearing loss, ringing in the ears (tinnitus), and balance problems. Bilateral acoustic neuromas (schwannomas affecting both vestibular nerves) are a hallmark of this condition.

Other common features include:

1. Meningiomas: These are tumors that grow in the meninges, the protective layers surrounding the brain and spinal cord.
2. Ependymomas: These are tumors that develop from the ependymal cells lining the ventricles (fluid-filled spaces) in the brain or the spinal cord canal.
3. Neurofibromas: Unlike in Neurofibromatosis type 1, these are less common and typically don't become cancerous.
4. Skin changes: While not as prevalent as in NF1, some people with NF2 may have skin freckles, café-au-lait spots, or skin tumors.
5. Eye problems: Some individuals may experience cataracts, retinal abnormalities, or optic nerve tumors (optic gliomas).
6. Other potential symptoms: Headaches, facial weakness or numbness, and difficulty swallowing or speaking.

NF2 is an autosomal dominant disorder, meaning that a person has a 50% chance of inheriting the condition if one of their parents has it. However, about half of all NF2 cases result from spontaneous genetic mutations with no family history of the disorder.

Soft tissue neoplasms refer to abnormal growths or tumors that develop in the soft tissues of the body. Soft tissues include muscles, tendons, ligaments, fascia, nerves, blood vessels, fat, and synovial membranes (the thin layer of cells that line joints and tendons). Neoplasms can be benign (non-cancerous) or malignant (cancerous), and their behavior and potential for spread depend on the specific type of neoplasm.

Benign soft tissue neoplasms are typically slow-growing, well-circumscribed, and rarely spread to other parts of the body. They can often be removed surgically with a low risk of recurrence. Examples of benign soft tissue neoplasms include lipomas (fat tumors), schwannomas (nerve sheath tumors), and hemangiomas (blood vessel tumors).

Malignant soft tissue neoplasms, on the other hand, can grow rapidly, invade surrounding tissues, and may metastasize (spread) to distant parts of the body. They are often more difficult to treat than benign neoplasms and require a multidisciplinary approach, including surgery, radiation therapy, and chemotherapy. Examples of malignant soft tissue neoplasms include sarcomas, such as rhabdomyosarcoma (arising from skeletal muscle), leiomyosarcoma (arising from smooth muscle), and angiosarcoma (arising from blood vessels).

It is important to note that soft tissue neoplasms can occur in any part of the body, and their diagnosis and treatment require a thorough evaluation by a healthcare professional with expertise in this area.

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