A case of intra-dural malignant peripheral nerve sheath tumor in thoracic spine associated with neurofibromatosis type 1

The Role of MRI in the Diagnosis of Spinal Cord Tumors

Spinal cord tumors are uncommon, and its multiple representatives not always have pathognomonic characteristics, which poses a challenge for both patients and caring physicians. The radiologist performs an important role in recognizing these tumors, as well as in differentiating between neoplastic and non-neoplastic processes, supporting clinical and surgical decision-making in patients with spinal cord injury. Magnetic Resonance Imaging (MRI) assessment, paired with a deep understanding of the various patterns of cord involvement allied to detailed clinical data can provide a diagnosis or significantly limit the differential diagnosis in most cases. In this article, we aim to review the most common and noteworthy intramedullary and extramedullary spinal tumors, as well as some other tumoral mimics, with an emphasis on their MRI morphologic characteristics.

Recent advances in intradural spinal tumors

Intradural spinal tumors are rare tumors of the central nervous system. Due to the eloquence of the spinal cord and its tracts, the compact architecture of the cord and nerves, and the infiltrative nature of some of these tumors, surgical resection is difficult to achieve without causing neurological deficits. Likewise, chemotherapy and radiotherapy are utilized more cautiously in the treatment of intradural spinal tumors than their cranial counterparts. Targeted therapies aimed at the genetic alterations and molecular biology tailored to these tumors would be helpful but are lacking.Here, we review the major types of intradural spinal tumors, with an emphasis on genetic alterations, molecular biology, and experimental therapies for these difficult to treat neoplasms.

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.

Radiation-induced intradural malignant peripheral nerve sheath tumor of the cauda equina with diffuse leptomeningeal metastasis

Malignant peripheral nerve sheath tumors (MPNSTs) are rare, affecting only a small portion of the general population. In many cases, MPNSTs occur in association with neurofibromatosis Type 1 and at times arise secondary to previous radiation therapy (RT). These tumors can be found essentially anywhere a peripheral nerve is present, but they rarely originate primarily from the spinal nerve or cauda equina and cause leptomeningeal spread. This report describes the treatment course of a 43-year-old man with a history of testicular seminoma treated with RT a decade before, who was found to have a large sacral MPNST. The patient underwent complete sacrectomy for gross-total resection. Despite this effort, he was eventually found to have metastatic lesions throughout the spine and brain, ultimately resulting in acute hydrocephalus and death. Biopsy results of these metastatic lesions proved to be characteristic of his original MPNST. The literature is also reviewed and the diagnostic modalities, management strategies, and prognosis of MPNST are discussed.

Favorable outcome after radical resection and subsequent local irradiation of malignant peripheral nerve sheath tumor in the cervical spine

A 25-year-old man presented with malignant transformation to malignant peripheral nerve sheath tumor (MPNST) in the cervical spine associated with neurofibromatosis type 1. He presented with a 3-week history of rapidly increasing weakness and numbness in all four extremities. Magnetic resonance (MR) imaging of the cervical spine demonstrated a dumbbell-shaped tumor, which compressed the spinal cord at the C2-3 level. The tumor was excised, mainly within the spinal canal to decompress the spinal cord. The histological diagnosis was benign neurofibroma. Three months after surgery, he rapidly developed progressive tetraparesis and MR imaging revealed marked regrowth of an extradural mass into the spinal canal. At reoperation, the regrown mass in the spinal canal was totally excised. The histological diagnosis revealed MPNST. He underwent radiation therapy, with a total dose of 32 Gy, for approximately 3 weeks after the second surgery, but MR imaging showed tumor regrowth within the spinal canal, and his condition deteriorated. The decision was made to remove the tumor radically, including the involved facet and extradural lesion. Posterior fusion using a pedicle screw was performed one month later. He manifested no additional neurological deficits. He has been free of relapse for 46 months. Radical resection remains the most effective treatment for MPNST, although complete removal with a clear tumor margin is often impossible in practice.

Malignant transformation of benign intraosseous schwannoma in the cervical spine: a case report with an immunohistochemical study

Although 3% to 30% of lesions in von Recklinghausen disease undergo malignant transformation, malignant transformation of benign solitary schwannoma is extremely rare. We reported a case of recurrence and malignant transformation in a benign intraosseous schwannoma arising in the cervical spine of a 44-year-old man. The patient presented giant tumor in the C3 vertebral body with aggressive, expansile, and osteolytic destruction and relapsed 2 years after surgical resection and spinal reconstruction. Clinical data, radiologic characteristics, surgical management, histopathologic and immunohistochemical features were noted in the duration of follow-up. The local recurrence, nuclear pleomorphism, epithelioid differentiation, a small number of positive S-100 protein-staining cells, and especially the high percentage of positive cells with p53 (80%) and Ki-67 (75%) proteins support the aggressive nature of the lesion in malignant transformation of benign intraosseous schwannoma in the cervical spine. Immunohistochemistry would be useful as an ancillary technique in diagnosis. It is our practice to suggest that such case has to be carefully resected and the patient followed up.

Primary malignant peripheral nerve sheath tumor of the cauda equina with metastasis to the brain in a child: case report and literature review

BACKGROUND CONTEXT

Primary intradural malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare; only 23 cases have been reported in the English-language literature till now. No gold standard for treating primary intradural MPNSTs has yet been established.

PURPOSE

To report a rare case of primary intradural MPNSTs in a child and review the literature pertaining to this rare disease.

STUDY DESIGN/SETTING

Case report and literature review.

METHODS

We report our experience with one new case. An 8-year-old boy diagnosed with primary intradural MPNSTs underwent three surgical excisions and two rounds of radiotherapy; however, metastasis to the brain was found, and the boy died 16 months after the first surgery. We also review the literature pertaining to both MPNSTs in general and primary intradural MPNSTs.

RESULTS

Surgery is currently the mainstay of MPNST treatment. Radiotherapy and chemotherapy are of limited value in these tumors. Based on the review of the 24 cases described in the literature, including the present case, primary intradural MPNST is a very aggressive tumor with a very high recurrence rate even after gross total resection and with significant potential for leptomeningeal and systemic metastasis. The overall prognosis is very poor and seems to be worse than that of MPNSTs in general.

CONCLUSIONS

Primary intradural MPNST is a very rare entity with a poor prognosis. Surgical tumor removal combined with postoperative high-dose radiation may be recommended. Chemotherapy is usually reserved for patients with disseminated metastases or tumors that are unresectable at the time of diagnosis.

Low-grade malignant triton tumor in the lumbar spine: a rare variant of malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon type of sarcoma that arises from peripheral nerve sheaths and rarely involves the spinal roots. The origin of this tumor is thought to be Schwann cells or pluripotent cells of the neural crest. The subgroup of tumors in which malignant Schwann cells coexist with malignant rhabdomyoblasts is termed malignant triton tumor (MTT). MPNSTs can show different degrees of malignancy, but overall spinal MTTs are high-grade lesions. We report the exceptional instance of a spinal low-grade MTT in a 39-year-old man treated with total surgical removal followed by local radiation therapy. Histological low grade was based on the lack of necrosis, a low grade of atypia, a low mitotic rate and a Ki-67 labelling index <25%. After 18 months of follow-up the patient is alive with no evidence of disease. A thorough review of the literature yielded 57 well-documented spinal MPNSTs. Ten of them corresponded to MTTs, but none showed low-grade features. An analysis of the clinical, radiological and treatment data was performed to identify factors that might influence the outcome. Overall the 18-month survival rate was 45% but dropped to 0% in the subgroup of spinal MTTs. Besides, a size exceeding 2 cm, extra-spinal extension, association with neurofibromatosis and subtotal removal were all related to a worse outcome. In conclusion, spinal MTTs generally exhibit a more aggressive behavior than conventional MPNSTs. The occurrence of a spinal low-grade MTT with a better prognosis should also be recognized.

Primary pediatric intraspinal sarcomas. Report of 3 cases

Sarcomas that arise from within the spinal canal are rare, particularly within the pediatric population. In general, these primary intraspinal sarcomas are highly aggressive, posing unique treatment challenges with respect to surgery and choice of adjuvant therapy. The goal must be to obtain the most complete resection possible to minimize the risk of recurrence and metastasis, while preventing potential neurological deficits that may result from aggressive surgery. Among these primary intraspinal sarcomas are malignant peripheral nerve sheath tumors and members of the Ewing sarcoma family of tumors. The authors present 3 cases of unique spinal sarcomas in children-2 malignant peripheral nerve sheath tumors in patients without neurofibromatosis and an intradural extraosseous Ewing sarcoma arising from the sensory component of a lumbar spinal nerve-and discuss their management and outcome with a review of the current literature.

An intraosseous malignant peripheral nerve sheath tumor of the cervical spine: a case report and review of the literature

STUDY DESIGN

Case description.

OBJECTIVES

To report a rare case of intraosseous malignant peripheral nerve sheath tumors (MPNST), and review the pertinent medical literature.

SUMMARY OF BACKGROUND DATA

The spinal MPNST that develops from spinal nerve roots and secondary bony erosion is well-known entity. However, primary intraosseous MPNSTs of the spine are extremely rare.

METHODS

A 41-year-old male presented with a 1-month history of radiating pain to his right shoulder and arm. Magnetic resonance images showed a large extradural mass extending from C6 to T1 with destruction of the posterior elements of C6, C7, and T1. Complete excision of the tumor and posterior stabilization were performed through a posterior approach. The tumor was noted to originate from the posterior element of C7.

RESULTS

The histopathology was diagnostic for a MPNST. Adjuvant chemotherapy was administered after surgery. The patient remained symptom-free for 30 months after surgery without local recurrence or metastasis.

CONCLUSION

We report an intraosseous MPNST of the cervical spine. Complete surgical excision and adjuvant chemotherapy resulted in a good functional outcome. MPNST should be added to the differential diagnosis of primary bone tumors causing spinal cord compression.