Squash preparation of a malignant triton tumor in a rare location

Abstract

Malignant peripheral nerve sheath tumors (MPNST) are rare malignant mesenchymal neoplasms of neural origin. Malignant peripheral nerve sheath tumors arising in a cranial nerve are rare with only a few cases being reported in literature. An MPNST with rhabdomyosarcomatous differentiation is also known as malignant triton tumor (MTT). MTT has a worse prognosis than the classic MPNST. The cytomorphological patterns of these tumors are insufficiently documented in literature. We present here the cytohistological features of an MPNST with focal rhabdomyomatous differentiation arising in the trigeminal nerve, which was confirmed by immunohistochemistry.