CASE 17751 Published on 10.06.2022
0

Intracranial malignant peripheral nerve sheath tumor

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Natanael Vázquez1, Omar Sanchez1, Marco Lopez2

1. High Specialty Regional Hospital of el Bajio, Leon, Guanajuato, Mexico

2. University of Guanajuato, Leon, Guanajuato, Mexico

Connected authors
User picture
Adolfo Vázquez Tobías Radiologist Mexico
Patient

18 years, male

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR
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Clinical History

An 18-year-old patient with neurofibromatosis type 1 was sent for MRI evaluation since a CT scan (not shown) revealed a large left frontal lesion.

Imaging Findings

MRI scan of the brain showed a large, irregular, heterogeneous, avidly enhancing left frontal lesion with extensive vasogenic oedema that caused both falcine and left descending uncal herniation

Discussion

Malignant peripheral nerve sheath tumours (MPNST) are rare, aggressive soft tissue sarcomas that arise from a peripheral nerve; they can originate from a pre-existing peripheral nerve sheath tumour, or from a neurofibroma in the case of neurofibromatosis type 1 [1]. They represent about 2% of sarcomas. Intracranial MPNST are even more exceptional, with very few cases reported in the literature. The median age for sporadic cases is 30-60 years, while it is between 20 to 40 years in the case of NF-1.

Clinical signs are variable, depending of the location and the nerve involved. The aggressive nature of the tumour will cause signs of intracranial hypertension. There is also rapid infiltration of surrounding tissues, bone erosion and/or infiltration, and hematogenous metastases, being the lungs the primary site for them. Full neuroaxis evaluation is requiered since the spinal chord is also a common site for metastases.  [3].

Imaging features are non-specific, with most case reports describing a lesion of irregular shape, with necrotic central areas, some calcified regions, and peripheral solid enhancing areas with high diffusion restriction, making it very hard to distinguish from high-grade gliomas o gliosarcomas [3,4]. Because of this, histopathological evaluation remains the main diagnostic tool.

The rarity of the tumour makes it very hard to have a treatment protocol, being complete resection with the aim of achieving negative resection margins the main goal. Adjuvant radiotherapy, particularly in cases of positive surgical margins is recommended [5]. Most patients will die within 5 years from diagnosis.

Conclusion

Intracranial malignant peripheral nerve sheath tumours are an extremely rare entity, with very poor prognosis. Imaging features are non-specific. However, when a highly infiltrative intracranial tumour is identified, particularly in a patient with NF-1, the differential diagnosis must be considered.

Written informed patient consent for publication has been obtained.

Differential Diagnosis List
Intracranial malignant peripheral nerve sheath tumour
Gliosarcoma
High-Grade Glioma
High-Grade Meningioma
Solitary Fibrous Tumor
Final Diagnosis
Intracranial malignant peripheral nerve sheath tumour
Case information
URL: https://www.eurorad.org/case/17751
DOI: 10.35100/eurorad/case.17751
ISSN: 1563-4086
License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Coronal T2-weighted image of the brain showing an irregular, heterogeneous, left frontal lesion with prominent vasogenic edem
Coronal T2-weighted image of the brain showing an irregular, heterogeneous, left frontal lesion with prominent vasogenic edema and marked mass effect causing subfalcine herniation
Sagital T2 weighted image of the brain shows the lesion having heterogeneous signal intensity, with some signal voids represe
Sagital T2 weighted image of the brain shows the lesion having heterogeneous signal intensity, with some signal voids representing blood vessels. The lesion eroded the frontal bone, protruding through it and reaching the subcutaneous tissue, causing marked bulging. It also erodes the sphenoid, reaching the sphenoid sinus
Axial FLAIR-weighted image of the brain shows the left frontal lesion with multiple blood vessels coursing through it, extens
Axial FLAIR-weighted image of the brain shows the left frontal lesion with multiple blood vessels coursing through it, extensive vasogenic edema and causing severe mass effect with compression of the ipsilateral basal ganglia and falcine herniation
Coronal T2 weighted image of the brain in a more caudal plane shows vasogenic edema with mass effect causing displacement of
Coronal T2 weighted image of the brain in a more caudal plane shows vasogenic edema with mass effect causing displacement of the midline structures as well as descending uncal herniation
Axial postgadolinium T1 weighted image of the brain showing heterogeneous enhancement of the lesion, predominant on the perip
Axial postgadolinium T1 weighted image of the brain showing heterogeneous enhancement of the lesion, predominant on the periphery of it
Sagittal postgadolinium T1 weighted image of the brain showing heterogeneous enhancement of the lesion, predominant on the pe
Sagittal postgadolinium T1 weighted image of the brain showing heterogeneous enhancement of the lesion, predominant on the periphery of it