epithelioid MPNST
Epithelioid MPNST shows a lobular architecture, epithelioid cytomorphology, prominent nucleoli, and S100 and/or GFAP expression.
Occasional cases may have myxoid stroma or rhabdoid cytomorphology.
Epithelioid MPNSTs are generally cytologically uniform. Many cases have an identifiable nerve of origin and/or focal fascicular spindle cell areas typical of conventional MPNST.
Epithelioid MPNST virtually always shows strong and diffuse positivity for S100 and only infrequently expresses epithelial markers.
See also
malignant peripheral nerve sheath tumor (MPNST)