Malignant nerve sheath tumor of the spinal accessory nerve: a unique presentation of a rare tumor

Malignant Peripheral Nerve Sheath Tumor Arising in Schwannomatosis with Multiple Lung Metastases

BACKGROUND

Malignant peripheral nerve sheath tumor (MPNST) is a kind of rare neurogenic malignancy, which usually arises from nerve fibers in any tissue and organ that have nerve fiber distributions, especially the trunk and extremities, but it is extremely rare in spinal canal.

CASE DESCRIPTION

We report a 30-year-old woman who had a history of excision of intraspinal occupying lesions 5 times and the pathologic diagnosis based on histomorphologic and immunohistochemistry was schwannomatosis, which existed in her family history. Unfortunately, she died because her condition deteriorated rapidly and appeared multiple lung metastases. MPNST was confirmed by needle biopsy of lung lesions.

CONCLUSIONS

Many cases of MPNST usually developed from neurofibromatosis type 1. However, the incidence of MPNST arising from schwannomatosis was extremely rare. More significantly, using genetic testing on her, we found a splice site mutation (c.1118+1G>A) that occurred between exons 8 and 9 of the SMARCB1 gene, which was first found in this MPNST patient and could lay the foundation for further study of its pathogenesis.

Tumor targeted delivery of doxorubicin in malignant peripheral nerve sheath tumors

Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs). Interleukin-13 receptor alpha 2 (IL13Rα2) is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC) and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR) was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR). This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.

Acute hydrocephalus due to a primary malignant peripheral nerve sheath tumor of the cervicothoracic junction: A case report and review of the literature

BACKGROUND

The estimated incidence of malignant nerve sheath tumors is 0.001% per year, and only 2-3% of those tumors involve the spinal nerves. We present a rare case of acute hydrocephalus caused by primary malignant peripheral nerve sheath tumor of the cervicothoracic junction.

CASE DESCRIPTION

A 29-year-old previously healthy male patient, except for a history of two previous surgeries for ulnar nerve entrapment and progressive left upper extremity weakness, presented with acute onset somnolence. The CT and MRI revealed hydrocephalus and periventricular edema. The patient underwent ventriculoperitoneal shunt surgery. Postoperative MRI of the spine revealed a 6×3×3cm intra-extradural lesion at C7-T1 level and multiple metastases in other spinal segments. The patient underwent combined surgical excision and the tumor was diagnosed as a malignant peripheral nerve sheath tumor based on pathological and immunohistological findings. Radiation therapy and chemotherapy were initiated.

CONCLUSION

Primary malignant peripheral nerve sheath tumor of the spine is a very aggressive tumor with a very high recurrence rate, significant potential for metastasis and very poor overall prognosis. They may present with features of more frequent diseases, such as peripheral neuropathies and may be overlooked as in our case. Thus, suspected cases should undergo a more detailed examination.

Angiographically occult vascular malformation of the intracranial accessory nerve: case report

Angiographically occult cerebral vascular malformations (AOVMs) are usually found in the supratentorial brain parenchyma. Uncommonly, AOVMs can be found within the cavernous sinus or basal cisterns and can be associated with cranial nerves. AOVMs involving the intracranial segment of the spinal accessory nerve have not been described. A 46-year-old female patient presented with a history of episodic frontal headaches and episodes of nausea and dizziness, as well as gait instability progressing over 6 months prior to evaluation. Imaging revealed a well-circumscribed 3-cm extraaxial T1-weighted isointense and T2-weighted hyperintense contrast-enhancing mass centered in the region of the right lateral cerebellomedullary cistern. The patient underwent resection of the lesion. Although the intraoperative appearance was suggestive of a cavernous malformation, some histological findings were atypical, leading to the final diagnosis of vascular malformation, not otherwise specified. The patient's postoperative course was uneventful with complete resolution of symptoms. To the authors' knowledge, this is the first report of an AOVM involving the intracranial portion of the accessory nerve. For any AOVM located within the cerebellomedullary cistern or one suspected of involving a cranial nerve, the authors recommend including immunohistochemistry with primary antibody to neurofilament in the histopathology workup.

Primary malignant peripheral nerve sheath tumor of the spine with acute hydrocephalus: a rare clinical entity

Primary malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare in patients without a history of neurofibromatosis; only 18 cases have been reported in the English-language literature to this point. The authors report their experience with 1 new case of a primary MPNST. A 33-year-old woman presented with low-back pain radiating to the right calf that progressed over 1 year. Magnetic resonance imaging of the spine revealed an intradural extramedullary lesion at the T12–L1 level. The patient was diagnosed with primary MPNST, underwent two surgical excisions and radiation therapy, and developed leptomeningeal metastases as well as brain metastases. The patient revisited the emergency room with sudden loss of consciousness. A brain CT scan displayed bilateral lateral ventricle enlargement, for which a ventriculoperitoneal shunt was inserted. These symptoms have not been described in any previous report. Primary spinal MPNST is an exceedingly rare entity, and the overall prognosis is very poor. To the authors' knowledge, no standard of care for primary spinal MPNSTs has yet been established. All 19 cases of primary spinal MPNSTs are reviewed, and the authors discuss their clinical, radiological, and therapeutic features and outcomes.

Primary malignant peripheral nerve sheath tumor at unusual location

Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue sarcoma. Most arise in association with major nerve trunks. Their most common anatomical sites are the proximal portions of the upper and lower extremities and the trunk. MPNSTs have rarely been reported in literature to occur in other unusual body parts. We review all such cases reported till now in terms of site of origin, surgical treatment, adjuvant therapy and outcome and shortly describe our experience with two of these cases. Both of our case presented with lump at unusual sites resembling neurofibroma, one at orbitotemporal area and other in the paraspinal region with characteristic feature of neurofibroma with the exception that both had very short history of progression. They underwent gross total removal of the tumor with adjuvant radiotherapy postoperatively. At 6-month follow-up both are doing well with no evidence of recurrence.

A case report of a malignant peripheral nerve sheath tumor of the oral cavity in neurofibromatosis type 1

Patients with neurofibromatosis type 1 develop both benign and malignant tumors at an increased frequency. Most of the malignant peripheral nerve sheath tumors (MPNSTs) are considered as high-grade sarcomas originating from tissues of mesenchymal origin. It is generally accepted that MPNSTs occur in about 2% to 5% of neurofibromatosis patients. In this paper, we present a 16-year-old male patient with neurofibromatosis who developed MPNST of the retromolar area. The mass enlarged rapidly in a period of 6 weeks. The patient was treated surgically, and a tumor mass with a diameter of 7 × 6 × 4 cm was excised, but after 8 months a recurrence was observed at the same site. The sarcomatous change in a neurofibroma has an extremely poor prognosis, so patients with neurofibromatosis should be closely monitored for a possible malignancy. A rapid change in size of a preexisting neurofibroma, infiltration of the adjacent structures, intralesional hemorrhage, and pain indicate a possible malignant transformation to MPNST.