Malignant Peripheral Nerve Sheath Tumor of the Pancreas: A Case Report

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Malignant peripheral nerve sheath tumor (MPNST) is rare, soft tissue, spindle cell sarcoma of an ectomesenchymal origin. MPNSTs frequently occur in the extremities and trunk, whereas there has been only one previous report of MPNST originated from the pancreas. A 55-yr-old previously healthy man was admitted for a pancreas head mass, which was detected during a routine health inspection. Fine needle aspiration biopsy showed atypical cells that were suspicious for malignancy. On open exploration, a 2.6cm sized hypervascular well capsulated mass was seen between the duodenal first portion and the pancreas head, and so enucleation was performed. The tumor was composed with spindle cells without a typical storiform pattern and the cells were positive for mesenchymal antigen, S-100 and vimentin, whereas they were negative for epithelial membrane antigen and cytokeratin. It was concluded that the tumor was a MPNST with perineural cell differentiation. Primary MPNST of the pancreas is extremely rare and performing immunohistochemical staining is necessary for making its diagnosis.