The American journal of surgical pathology
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Am. J. Surg. Pathol. · Oct 2009
Hybrid schwannoma/perineurioma: clinicopathologic analysis of 42 distinctive benign nerve sheath tumors.
Benign nerve sheath tumors include neurofibromas, schwannomas, and perineuriomas. In recent years, nerve sheath tumors showing discrete areas of more than one histologic type have been described. We have recently recognized tumors showing hybrid features of schwannoma and soft tissue perineurioma. ⋯ Degenerative nuclear atypia (akin to that seen in ancient schwannoma and atypical neurofibroma) is relatively common. Hybrid schwannoma/perineuriomas have no evident association with neurofibromatosis and rarely recur. The pathogenetic basis of the dual pattern of differentiation in these lesions remains poorly understood at this time.