Malignant triton tumor of the lumbar spine.

STUDY DESIGN

A case report of surgically treated malignant triton tumor of the L2 nerve root.

OBJECTIVES

To discuss treatment methods of the rare malignant triton tumor.

SUMMARY OF BACKGROUND DATA

Malignant peripheral nerve sheath tumors are neoplasms that most often arise in peripheral nerves or in neurofibromas. Malignant triton tumor is a histologic variant of those tumors.

METHODS

A 58-years-old male patient was admitted with severe back and leg pain. Magnetic resonance imaging revealed a dumbbell-shaped tumor over the right L2 nerve root. The tumor mass was removed posteriorly and the spine was stabilized by transpedicular screws followed by radiation therapy.

RESULTS

The tumor was diagnosed as "malignant triton tumor." There was no sign of metastasis during the 8 months of follow up.

CONCLUSIONS

In this case, the diagnosis of triton tumor is based solely on microscopic evidence of the neural tissue accompanied by rhabdomyoblasts and immunohistochemical examination. Patients with malignant triton tumors are usually younger than age 35. Our patient is 1 of the oldest patients with tumor occurrence in the spinal canal. Although our patient still has no evidence of recurrence, the prognosis is poor for this group of patients.