Home » Patient Resources » What is sarcoma? » Soft Tissue Sarcoma Reference Guide » Malignant Peripheral Nerve Sheath Tumors (MPNST)
Chapter 9: Malignant Peripheral Nerve Sheath Tumor (MPNST)
MPNST sarcomas arise from the insulating cells that surround nerve endings. They can occur in people who have a familial disposition to forming benign versions of these tumors called neurofibromas or schwannomas. This condition is called neurofibromatosis type I and carries with it the risk of developing MPNSTs and other tumors, such as relatively less aggressive tumors that affect the brain or nerve sheaths of nerve endings as they leave the brain, but within the skull.
Alternative diagnostic termsMalignant Schwannoma
Common anatomical locationsTrunk and extremities
Pathology commentOften arises from a peripheral nerve, from a pre-existing benign nerve sheath tumor, or in a patient with neurofibromatosis type 1 (NF1). In the sporadic setting, diagnosis is most often based on the identification of Schwann cell differentiation (S100/SOX10 focal positivity) and/or loss of H3K27me3 expression in a soft tissue mass.
SourceAntonescu CR, Nielsen GP, Chi P. Malignant peripheral nerve sheath tumor. In: WHO Classification of Tumors Editorial Board. Soft tissue and bone tumors [Internet]. Lyon (France): International Agency for Research on Cancer; 2020 [2024 Dec 29]. (WHO Classification of Tumors Series, 5th ed.; vol. 3). Available from: https://tumorclassification.iarc.who.int/chapters/33
For diagnosis or treatmentAny center listed in the Sarcoma Centers Directory »
Patient advocacyAny organization with an established program for patient triage, support, and education. See Patient Advocacy Directory »
Clinical trialsSARC Clinical Trials – NoneFind clinical trials worldwide »
Alternative diagnostic termsMalignant Melanotic Schwannian TumorMelanotic SchwannomaPsammomatous Melanotic Schwannoma
Common anatomical locationsSpinal or autonomic nerves near the midline than upper extremities.
Pathology commentVariably associated with Carney complex and frequently shows aggressive clinical behavior. PRKAR1A mutations and loss of PRKAR1A protein expression are seen in the overwhelming majority of cases.
SourceAntonescu CR, Folpe AL, Hameed M. Malignant melanotic nerve sheath tumor. In: WHO Classification of Tumors Editorial Board. Soft tissue and bone tumors [Internet]. Lyon (France): International Agency for Research on Cancer; 2020 [2024 Dec 29]. (WHO Classification of Tumors Series, 5th ed.; vol. 3). Available from: https://tumourclassification.iarc.who.int/login?redirecturl=%2Fchapters%2F33
Clinical trialsSARC Clinical Trials – SARC032-SU2C Soft Tissue Sarcoma of the ExtremityFind clinical trials worldwide »
Alternative diagnostic termsSchwannomaPerineuriomaGranular Cell TumorMeningothelial HamartomaBenign Triton Tumor
Common anatomical locationsPending
Pathology commentPending
SourcePending