Malignant triton tumor (MTT) is a relatively rare, aggressive tumor made up of both malignant schwannoma cells and malignant rhabdomyoblasts. It's classified as a malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation.
The unusual name "triton" was first used in reference to observation of supernumerary limbs containing bone and muscle growing the backs of tritons after the implantation of the sciatic nerve into the soft tissues of the back.
There are three diagnostic criteria proposed: