Malignant peripheral nerve sheath tumor arising in a "de novo" ganglioneuroma. A case report.

A case of a "de novo" ganglioneuroma showing an internal area of malignant nerve sheath tumor is described. The tumor arose in an 18-year-old girl without a history of von Recklinghausen's disease. Immunohistochemically, the ganglioneuromatous component was positive with anti-synaptophysin, anti-S100 protein and anti-vimentin antisera, whereas the malignant part was immunoreactive only with anti-S100 protein and anti-vimentin antisera. The patient is free of disease 4 years after surgery. The clinicopathologic features of this rare case are discussed.