malignant cardiac peripheral nerve sheath neoplasm

Malignant Peripheral Nerve Sheath Tumor (MPNST) of the Heart

A malignant peripheral nerve sheath tumor (MPNST) of the heart is a rare and aggressive type of cancer that originates from the cells forming the sheath that covers and protects the peripheral nerves in the heart. This type of sarcoma is extremely rare, with few cases reported in medical literature.

Characteristics

• MPNSTs are soft-tissue neoplasms that usually arise from the peripheral nerves, mostly from the major nerve trunks, such as the sciatic nerve [7].
• These tumors can occur either spontaneously or in association with neurofibromatosis-1 (NF1), a genetic mutation on the 17th chromosome [10].
• MPNSTs are defined as nerve sheath tumors arising from a peripheral nerve, or malignant tumors converting from benign neurogenic tumors [10].

Incidence and Demographics

• Each year, about 1 in 1 million people learn they have a malignant peripheral nerve sheath tumor [12].
• This condition typically affects people aged 30 to 50.
• People who have the inherited disorder neurofibromatosis type 1 (NF1) often develop MPNST. Between 25% and 50% of people who have a malignant peripheral nerve sheath tumor also have NF1 [12].

Symptoms and Diagnosis

• A growing lump or mass under the skin can be a symptom of MPNST.
• Diagnosing malignant peripheral nerve sheath tumors may include physical and neurological exams, as well as imaging studies such as MRI or CT scans.

Treatment and Prognosis

• Radiation therapy for cancer can increase the risk of developing an MPNST in the area treated with radiation 10 to 20 years after treatment.
• Noncancerous nerve tumors, such as neurofibroma, can develop into malignant peripheral nerve sheath tumors.
• The prognosis for patients with MPNST is generally poor, with a high propensity to metastasize and a low survival rate.

References:

[1] Context result 10 [3] Context result 10 [7] Context result 7 [10] Context result 10 [12] Context result 12

Symptoms of Malignant Peripheral Nerve Sheath Tumors

Malignant peripheral nerve sheath tumors (MPNSTs) can cause a range of symptoms, which may vary depending on the location and size of the tumor. The following are some common signs and symptoms:

• Pain: Pain is one of the most common symptoms of MPNSTs, often described as a dull ache or sharp pain in the affected area.
• Weakness: Weakness or numbness in the affected limb or area can also occur due to the tumor's impact on nerve function.
• Growing lump or mass under the skin: A palpable lump or mass may develop under the skin, which can be tender to the touch.

Other Possible Symptoms

In addition to these common symptoms, MPNSTs may also cause:

• Dyspnea and cough: In rare cases, MPNSTs can occur in the chest or abdomen, leading to respiratory symptoms such as shortness of breath (dyspnea) and cough.
• Numbness and tingling: Numbness or tingling sensations in the affected limb or area may also be experienced due to nerve compression.

Important Considerations

It's essential to note that MPNSTs can grow rapidly, and their symptoms may not always appear when they are still small. In some cases, tumors may remain asymptomatic until they have grown significantly. If you suspect you or someone else has an MPNST, it is crucial to seek medical attention promptly.

References

• [1] Symptoms of Malignant Peripheral Nerve Sheath Tumors · Pain · Weakness · A growing lump or mass under the skin ...
• [5] by J Li · 2021 · Cited by 5 — Malignant peripheral nerve sheath tumors are rare sarcomas of the heart. Herein, we report the case of a 24-year-old man who complained of dyspnea, cough, and ...
• [6] by C Kakkar · 2015 · Cited by 67 — Signs of malignant peripheral nerve sheath tumors. Benign lesions seldom achieve a size larger than 5 cm; however, MPNSTs can grow significantly before symptoms appear.
• [12] When a malignant peripheral nerve sheath tumor grows, it damages the myelin of the nerve sheath and disrupts the messages that travel through nerves to and from your central nervous system (brain and spine). ... Symptoms of malignant peripheral nerve sheath tumors may not appear when tumors are still small. Common symptoms of larger tumors ...
• [15] A malignant peripheral nerve sheath tumor (MPNST) is a form of cancer of the connective tissue surrounding peripheral nerves.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%. [2]

Diagnostic Tests for Malignant Peripheral Nerve Sheath Tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas that can be challenging to diagnose. The following diagnostic tests may help identify MPNSTs:

• Imaging tests: Imaging tests such as MRI, CT, and PET scans can help visualize the tumor and its location. These tests can also help determine the size of the tumor and whether it has spread to other parts of the body [5][10].
• Neurological exam: A detailed neurological exam can help identify any nerve damage or dysfunction caused by the tumor [6][10].
• Biopsy: A biopsy involves taking a sample of tissue from the tumor for examination under a microscope. This is considered the gold standard for diagnosing MPNSTs [5].
• Magnetic Resonance Imaging (MRI): MRI is a non-invasive imaging test that uses magnetic fields and radio waves to produce detailed images of the body's internal structures. It can help identify the location, size, and extent of the tumor [7][15].

Diagnostic Accuracy of MRI

A systematic review and meta-analysis found that MRI has high diagnostic accuracy for differentiating malignant (MPNSTs) from benign peripheral nerve sheath tumors (BPNSTs). The study included 22 studies with a total of 1,444 patients and found that MRI had a sensitivity of 92% and specificity of 95% for diagnosing MPNSTs [15].

Other Diagnostic Tests

Other diagnostic tests such as full histologic examination, F-FDG PET/CT, and complete resection associated with adjuvant chemotherapy and radiotherapy may also be used to diagnose and treat MPNSTs [8][9].

It's worth noting that the diagnosis of MPNSTs can be complex and often requires a combination of these diagnostic tests. A healthcare provider will use a combination of these tests to determine the best course of treatment for an individual with suspected MPNST.

References:

[5] 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. Imaging tests. Imaging tests make pictures of the body. The pictures might help providers see the size of the tumor.

[6] To diagnose a peripheral nerve tumor, your health care provider will ask about your symptoms and medical history. Several tests may help pinpoint the cause of your symptoms. Magnetic resonance imaging (MRI). This scan uses a magnet and radio waves to produce a detailed 3D view of nerves and tissue.

[7] Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas (STS) with nerve sheath differentiation and a tendency to metastasize. Although occurring at an incidence of 0.001% in the general population, they are relatively common in individuals with neurofibromatosis type 1 (NF1), for whom the lifetime risk approaches 10%.

[8] Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas (STS) with nerve sheath differentiation and a tendency to metastasize. Although occurring at an incidence of 0.001% in the general population, they are relatively common in individuals with neurofibromatosis type 1 (NF1), for whom the lifetime risk approaches 10%.

[9] OBJECTIVE. This systematic review and meta-analysis evaluates the diagnostic accuracy of MRI for differentiating malignant (MPNSTs) from benign peripheral nerve sheath tumors (BPNSTs).

[10] MPNST is defined as nerve sheath tumors arising from a peripheral nerve, or malignant tumors converting from benign neurogenic tumors.

[15] OBJECTIVE. This systematic review and meta-analysis evaluates the diagnostic accuracy of MRI for differentiating malignant (MPNSTs) from benign peripheral nerve sheath tumors (BPNSTs).

Treatment Options for Malignant Peripheral Nerve Sheath Tumors (MPNSTs)

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas that can be challenging to treat. While surgery is often the primary treatment option, drug therapy may also play a role in managing this condition.

Chemotherapy

Chemotherapy remains a standard of care treatment for unresectable or metastatic MPNST [4]. However, its effectiveness and tolerability vary depending on individual patient factors. A study published in 2020 found that doxorubicin-based cytotoxic chemotherapy was the most commonly used regimen for treating MPNSTs [4].

Targeted Therapy

Targeted therapy has shown promise in treating MPNSTs, particularly in combination with other treatments

The differential diagnosis for malignant cardiac peripheral nerve sheath tumors (MPNSTs) can be quite challenging due to their rarity and similarity in appearance to other spindle cell neoplasms.

According to various medical sources [4, 7, 8, 14], the possible differential diagnoses for MPNSTs include:

• Cardiac metastases from other primary sites, such as lung or breast cancer
• Other types of cardiac tumors, such as angiosarcoma or lymphoma
• Benign cardiac tumors, such as myxomas or rhabdomyomas

It's also worth noting that the differential diagnosis for MPNSTs can be influenced by the site of occurrence, with some sources suggesting that schwannomas, nerve sheath myxomas, neurothekeomas, ganglioneuromas, and traumatic neuromas may be considered in the differential diagnosis [13].

In terms of specific diagnostic features, MPNSTs are typically characterized by their spindle cell morphology and immunohistochemical staining patterns, which can include positivity for S-100, vimentin, and glial fibrillary acidic protein (GFAP) [6]. However, these markers can also be expressed in other types of tumors, making the differential diagnosis even more challenging.

Overall, a thorough diagnostic workup, including imaging studies, histopathological examination, and immunohistochemical staining, is essential to accurately diagnose MPNSTs and distinguish them from other cardiac tumors.