Malignant triton tumor in the thoracic spine.

We present a 15-year-old patient diagnosed with peripheral neurofibromatosis (NF-1), who was admitted with paraparesis caused by a large intrathoracic tumor with an intracanalicular component that affected the spinal cord. After surgery his condition improved, but a year later he suffered a relapse and died. Histologically the tumor was diagnosed as malignant with neurogenic and myogenic differentiation ("malignant triton tumor"). Malignant triton tumors (MTT) are infrequent; those found in the head and neck and the upper or lower extremities have a better prognosis than those in the retroperitoneum, buttock, or trunk. It is not clear whether this variation is due to a difference in tumor grade, stage, or resectability, or whether it is a consequence of therapy.