Intracranial malignant triton tumor in a patient with neurofibromatosis type 1: case report and review of the literature.

We report the fourth case of an intracranial malignant triton tumor not associated with a cranial nerve in a 26-year-old male with a clinical history of neurofibromatosis type 1. The patient was found unresponsive and displayed confusion, lethargy, hyperreflexia, and dysconjugate eye movements upon arrival at the emergency room. MRI revealed a large bifrontal mass. Biopsy demonstrated a high-grade spindle cell tumor with focal areas of rhabdomyoblasts that stained positive for desmin, myogenin, and muscle-specific actin. Electron microscopy showed skeletal muscle differentiation. Based on the clinical history of NF1 and the pathologic results, a diagnosis of malignant triton tumor was made. The differential diagnosis, immunohistochemistry, molecular genetics, and treatment of malignant triton tumor are reviewed.