Malignant intracerebral nerve sheath tumor in a patient with Noonan syndrome: illustrative case

Abstract

BACKGROUND Malignant peripheral nerve sheath tumors (MPNSTs) within the neuroaxis are rare, usually arising from peripheral and cranial nerves. Even more scarce are cranial subclassifications of MPNSTs termed “malignant intracerebral nerve sheath tumors” (MINSTs). These tumors are aggressive, with a strong tendency for metastasis. With this presentation, alongside resistance to adjunctive therapy, complete excision is the mainstay of treatment, although it is often insufficient, resulting in a high rate of mortality. OBSERVATIONS The authors report the case of an adult patient with a history of Noonan syndrome (NS) presenting with slowly progressive right-sided hemiparesis and right-sided focal motor seizures. Despite initial imaging and histology suggesting a left frontal lobe high-grade intrinsic tumor typical of a glioblastoma, subsequent molecular analysis confirmed a diagnosis of MINST. The patient’s neurological condition improved after gross-total resection and adjuvant chemo-radiation; he remains on follow-up. LESSONS MINSTs are rare neoplasms with a poor prognosis; management options are limited, with surgery being the cornerstone of treatment. Reports on rare tumors such as this will increase awareness of this particular pathology and disclose clinical experience. In this case, the authors were unable to establish a definite cause-and-effect relation between NS and MINST. Nevertheless, it remains the first reported case in the literature.

Malignant intracerebral nerve sheath tumour of the brain presenting as a recurrent meningioma

“…It was finally found to be IDH1-R132 and IDH2-R172 wild type on Sanger sequencing, with the absence of mutations in histone H3F3Agene or telomerase reverse transcriptase (TERT) promoter genes. 7 MINST are aggressive tumours with varying outcomes with many having a dismal prognosis 8 Sharma et al studied that the earlier the first recurrence, the worse the overall survival of the patient. Charles et al did a systematic review of 56 patients with intracranial MPNSTs from 743 literature results.…”