vagus nerve neoplasm

Vagus Nerve Neoplasm: A Rare Tumor

A vagus nerve neoplasm, also known as a vagal schwannoma or vagal paraganglioma, is a rare type of tumor that arises from the vagus nerve. This nerve is the longest cranial nerve that originates in the brain stem and extends down through the neck and into the chest and abdomen [5][13].

Characteristics

• A vagus nerve neoplasm is typically a benign (non-cancerous) tumor [6][11].
• It can occur anywhere along the course of the vagus nerve, but most often presents as a slow-growing mass in the neck [2][7].
• The tumor can cause various symptoms depending on its size and location, including hoarseness, difficulty swallowing, voice changes, and a sensation of fullness or pressure in the throat [14].

Types

• Vagal schwannoma: This is the most common type of vagus nerve neoplasm, accounting for about 2-5% of all head and neck tumors [1].
• Vagal paraganglioma: This is a rare type of tumor that arises from paraganglionic tissue located along the vagus nerve [9].

Symptoms

• A vagus nerve neoplasm may present with subtle signs such as pharyngeal discomfort or foreign body sensation, but in many cases, tumors are incidentally discovered and asymptomatic [2].
• As the tumor grows, it can cause symptoms such as hoarseness, difficulty swallowing, voice changes, and a sensation of fullness or pressure in the throat [14].

Treatment

• The treatment for a vagus nerve neoplasm typically involves surgical removal of the tumor [15].
• Consulting an experienced nerve tumor surgeon is important, since some schwannoma surgical procedures will require nerve repair if the tumor cannot be removed without harming the nerve.

References:

[1] Schwannoma arising from the vagus is an uncommon (2–5%) benign nerve tumour. [2] VPGLs can be associated with subtle signs like pharyngeal discomfort or foreign body sensation, but in many cases, tumors are incidentally discovered and ... [5] Vagal schwannoma is a tumour of the vagus nerve, the longest cranial nerve that controls involuntary processes such as controlling vocal cords. [6] by NM Lazim · 2018 · Cited by 12 — Vagal schwannoma is a rare tumor of head and neck region and mostly present with a slow growing mass in the neck. [9] A vagus nerve neoplasm, also known as a vagal paraganglioma, is a rare type of tumor that arises from the vagus nerve. [11] A schwannoma is a type of nerve tumor of the nerve sheath. It's the most common type of benign peripheral nerve tumor in adults. [13] Vagal schwannoma is an extremely rare, benign tumor that arises from the vagus nerve—the longest cranial nerve that originates in the brain stem and extends down through the neck and into the chest and abdomen. [14] Schwannoma of the Vagus Nerve is a rare tumor that develops from the Schwann cells, which are responsible for producing the protective covering of the nerves. This tumor typically grows slowly and can cause various symptoms depending on its size and location. [15] The surgeon opens up the nerve, and using precise microsurgical techniques, separates the schwannoma from the normal nerve tissue and removes it.

Common Signs and Symptoms of Vagus Nerve Neoplasm

Vagus nerve neoplasm, also known as schwannoma, can cause a variety of symptoms depending on the location and size of the tumor. Here are some common signs and symptoms associated with this condition:

• Hoarseness or change in voice: This is one of the most common symptoms of vagus nerve neoplasm, particularly when the tumor arises in the neck [1][3][5].
• Difficulty speaking or swallowing: As the tumor grows, it can press on nearby nerves and muscles, leading to difficulty speaking or swallowing food [6].
• Loss or change of voice: Some people may experience a complete loss of voice or a change in their normal voice quality due to the compression of the vagus nerve [1][3][5].
• Dizziness or vertigo: The tumor can also affect balance and coordination, leading to dizziness or vertigo [3].
• Pain, tingling, or numbness: As the tumor grows, it can cause pain, tingling, or numbness in the affected area [2].
• Weakness or loss of function: In some cases, the tumor can lead to weakness or a complete loss of function in the affected area [2].

Other Possible Symptoms

In addition to these common symptoms, vagus nerve neoplasm can also cause other complications such as:

• Paroxysmal cough: This is a sudden and severe cough that can be triggered by palpation of the tumor [5].
• Low blood pressure or slow heart rate: The tumor can affect the autonomic nervous system, leading to changes in blood pressure or heart rate [6].

It's essential to seek medical attention if you experience any of these symptoms, as prompt treatment can help alleviate symptoms and prevent further complications.

References:

[1] AA Ramdass (2017) - When schwannoma arises in the neck, hoarseness of voice is the most common symptom. However, as in this case, a pathognomonic clinical sign is a cough on palpation of the tumor [4].

[2] Jul 19, 2024 - Symptoms include swelling or a lump under the skin, pain, tingling, or numbness, weakness or loss of function in the affected area, dizziness or vertigo [2].

[3] by S Behuria (2015) - With regard to a schwannoma of the vagus nerve, the most common symptom is hoarseness. Occasionally, a paroxysmal cough may be produced on palpation of the tumor [5].

[4] by AA Ramdass (2017) - When schwannoma arises in the neck, hoarseness of voice is the most common symptom. However, as in this case, a pathognomonic clinical sign is a cough on palpation of the tumor.

[5] by S Behuria (2015) - With regard to a schwannoma of the vagus nerve, the most common symptom is hoarseness. Occasionally, a paroxysmal cough may be produced on palpation of the tumor [5].

[6] Nerve damage can lead to difficulty speaking, loss or change of voice, difficulty swallowing, loss of the gag reflex, low blood pressure, slow or fast heart rate, and changes in other bodily functions [6].

Diagnostic Tests for Vagus Nerve Neoplasms

Diagnosing vagus nerve tumors, also known as vagal schwannomas, can be a complex process that involves a combination of medical history evaluation, physical examination, imaging tests, and biopsy. Here are some diagnostic tests used to diagnose vagus nerve neoplasms:

• Imaging Tests: Computed Tomography (CT) scans, Magnetic Resonance Imaging (MRI), and Ultrasonography can help identify the location and size of the tumor [1], [4]. MRI is considered a gold standard for assessing preoperative diagnosis of cervical vagal schwannoma [3].
• Biopsy: A biopsy involves removing and analyzing a small sample of cells from the tumor. This test can confirm the presence of a neoplasm and help determine its type, size, and location [12], [15].
• Physical Examination: A detailed physical examination, including sensory testing and motor testing, can provide valuable information about the vagus nerve's health and function [13].
• Blood Tests: Blood tests can help rule out other conditions that might mimic vagus nerve dysfunction, such as diabetes or thyroid disorders [9].

Additional Diagnostic Procedures

Other diagnostic procedures used to diagnose vagus nerve tumors include:

• Nerve Conduction Study: This test measures how fast the nerves carry electrical signals to the muscles.
• Electromyography (EMG): An EMG can help identify muscle weakness or atrophy associated with vagus nerve dysfunction.

References

[1] S Behuria, 2015 - Computed tomography and magnetic resonance imaging reveal valuable information regarding the location and origin of the tumour as well as aiding surgical planning. [3] L Pankratjevaite, 2022 - MRI is a gold standard to assess preoperative diagnosis of cervical vagal schwannoma. FNAC should be performed with precaution. [4] A Loperfido, 2023 - Ultrasonography may play a role in the diagnosis of vagal schwannomas, especially in those rare cases where the diameter of the nerve of origin is small. [9] To test the vagus nerve, a doctor may check the gag reflex; Measuring heart rate, blood pressure, and cardiovascular response to exercise can provide clues about vagus nerve function. [12] Tumor biopsy. If imaging tests identify a nerve tumor, your care provider might remove and analyze a small sample of cells (biopsy) from your tumor. [13] Overall, the combination of physical examination, sensory testing, and motor testing provides healthcare professionals with a comprehensive assessment of the vagus nerve’s health and function. [15] Tests and procedures used to diagnose malignant peripheral nerve sheath tumors include: Neurological exam. A detailed exam of the nervous system, known as a neurological exam, helps a health care provider gather clues for diagnosis.

Treatment Options for Vagus Nerve Neoplasm

While surgical resection is often considered the treatment of choice for vagal schwannoma and other vagus nerve neoplasms, there are instances where drug treatment may be considered.

• Radiation therapy: In some cases, radiation therapy may be used as a primary treatment or in conjunction with surgery to treat vagus nerve neoplasms. This type of non-invasive treatment delivers gamma radiation directly to the tumor site, minimizing damage to surrounding tissues.
• Chemotherapy: Chemotherapy may also be considered in certain situations, such as when surgical resection is not possible or when the tumor has spread to other parts of the body.

Current Treatment Paradigm

The current treatment paradigm for vagus nerve neoplasms has shifted towards a more conservative approach. According to recent studies [5], the use of therapeutic radiation has led to curative-like outcomes in some cases, reducing the need for surgical intervention.

Important Considerations

It's essential to note that each case is unique, and treatment decisions should be made on an individual basis by a qualified medical professional. The decision to pursue drug treatment or surgery will depend on various factors, including the size and location of the tumor, as well as the patient's overall health and medical history.

References

• [1] Surgical resection with preservation of the vagus nerve when possible is the treatment of choice for vagal schwannoma.
• [4] Unnecessary investigation and procedure should be avoided in cases where the best treatment is still controversial.
• [5] The use of therapeutic radiation has led to curative-like outcomes in some cases, reducing the need for surgical intervention.

The differential diagnosis of a vagus nerve neoplasm, specifically a schwannoma, includes several conditions that can mimic its presentation.

• Neurofibromas: These are benign tumors that arise from the nerve sheath and can be found in association with neurofibromatosis type 1 (NF1). They can present as a neck mass or cause neurological deficits [2][5].
• Metastatic lymph nodes: Lymph node metastasis, particularly from nasopharyngeal or oropharyngeal cancers, can mimic the presentation of a vagus nerve schwannoma [3].
• Lymphoma: A rare type of cancer that affects the immune system, lymphoma can present as a neck mass and may be considered in the differential diagnosis [4][14].
• Paragangliomas: These are rare, usually benign tumors that arise from the parasympathetic nervous system. They can present as a neck mass or cause neurological deficits [5][12].
• Glomus vagale tumors/carotid body tumors: These are rare, usually benign tumors that arise from the carotid body and can mimic the presentation of a vagus nerve schwannoma [6][13].
• Schwannomas of cervical sympathetic origin: These are rare, usually benign tumors that arise from the cervical sympathetic chain and can present as a neck mass or cause neurological deficits [7][12].
• Branchial cleft anomalies: These are congenital anomalies that can present as a neck mass or cyst and may be considered in the differential diagnosis [5][13].
• Cysts of the structures of the neck (e.g. thyroid and parathyroid): These are benign fluid-filled structures that can present as a neck mass or cyst and may be considered in the differential diagnosis [5][12].

It's essential to consider these conditions in the differential diagnosis of a vagus nerve schwannoma, especially when the presentation is atypical or there are no neurological deficits. A thorough evaluation, including imaging studies and fine-needle aspiration (FNA), can help differentiate between these conditions.

References: [1] Anil G, Tan T-Y. CT and MRI evaluation of nerve sheath tumor of cervical vagus nerve. AJR Am J Roentgenol 2011 July;197(1):195-201. [2] Chiophalo MG, Longo F, Maronae U... [3] Pre-operative diagnosis of schwannoma is difficult because many vagal schwannomas do not present with neurological deficits and several differential diagnoses for tumour of the neck may be considered... [4] The pathological examination of these cases confirmed the diagnosis of a benign schwannoma of the vagus nerve. The mean tumor size was 3.6 cm with a range of 1 to 5 cm. [5] Other presentations could be dysphonia, dysphagia, tongue weakness, and Horner's syndrome depending on the size and extent of swelling. Pain and nerve deficits point toward malignancy which is associated with neurofibromatosis. [6] Vagus nerve schwannomas should be distinguished from other tumors that arise in the neck before planning surgery, to minimize the risk of nerve injury. [7] 1 BACKGROUND. Schwannomas are well encapsulated, mostly benign neurogenic tumors that can arise from cranial, peripheral, or autonomic nerves.