[Malignant triton tumor of the sinonasal tract]

The combination of a malignant peripheral nerve sheath tumor with rhabdomyosarcomatous elements has been termed Malignant Triton Tumor (MTT). This tumor was first reported in 1932 and the prognosis was poor. Involvement of the sinonasal tract is rare with only 10 case reports.

We report the case of a 80-year-old woman who presented an obstruction of the right nasal fossa which developed over several years without anosmia. She consulted because of recurrent epistaxis. The CT-scan revealed a tumor occupying the right ethmoid the right maxillary sinus and the homolateral nasal fossa. Resection was achieved via an extended mediofacial route. The histological diagnosis was low-grade schwannosarcoma with a discretely extended rhabdomyosarcomatous component, i.e. MTT. No complementary treatment was given. Eight months later, the tumor relapsed with cerebral involvement. Despite new surgery with two teams, a neurosurgical and a radiotherapy team, the tumor relapsed at the ethmoid-nasal level. After five years, the patient is alive with local progression without metastasis.

MTT of the sinonasal tract is a rare disease that clinicians should be aware of and that must be included in the differential diagnosis of malignant lesions involving the sinonasal tract. Most of the reported cases involving localizations other than the ethmoidonasal cavities, are associated with von Recklinhausen neurofibromatosis and occurr in young subjects (mean age 35 years). There have however been sporadic cases, mainly in older women or after radiotherapy. The prognosis is somewhat better for ethmoidonasal localizations.