Malignant triton tumor of the maxilla: a patient report

Malignant peripheral nerve sheath tumour of the oral and maxillofacial region-A systematic review

To integrate the available data published on malignant peripheral nerve sheath tumours (MPNST) of the oral and maxillofacial region. Searches in Embase, PubMed, Web of Science and Scopus were conducted for the identification of case reports/case series in English language. The risk of bias was assessed using the Joanna Briggs Institute tool. Outcomes were evaluated by Cox regression and Kaplan-Meier methods. A total of 306 articles were retrieved, 50 of which reporting 57 MPNST were included. The lesion showed a predilection for the mandible (n = 18/31.57%) of middle-aged adults (~40.5 years) with a male/female ratio of 1.1:1. The individuals were mostly symptomatic with a mean evolution time of 9.6 months. Surgical removal plus adjuvant therapy (especially radiotherapy) was the main approach (51.86%). Recurrence was reported in 39.62% of cases. Nodal and distant metastases were identified in 28.26% and 26.66% of cases, respectively. The 2-year cumulative survival rate was 55%. Independent predictors of poor survival were the presence of neurofibromatosis type 1 (p = 0.04) and distant metastases (p = 0.004). The diagnosis of MPNST is challenging due to the variety of its clinical and histopathological presentations. Local aggressiveness and the potential for metastases are common outcomes of this neoplasm.

[Malignant Triton tumor of the nose--case report]

Malignant Triton tumor (MTT) is classified as a variant of a malignant peripherial nerve sheath tumor with a focal rhabdomyosarcomatous differentiation. Nearly one third of described MTTs were located at the head and neck region. In following paper we described a case of MTT of the external nose in a 24 year old man. The tumor was totally exised surgically with the broad margins. Histopathological diagnosis of the tumor was made on the surgical specimen, based on immunohistochemical analysis. Radiation therapy as the next step of treatment of choice was performed in presented case.

Prognostic factors for the malignant triton tumor of the head and neck

BACKGROUND

Malignant triton tumors are rare neoplasias consisting of a malignant peripheral nerve sheath tumor with additional rhabdomyoblastic differentiation. These tumors are highly aggressive and prognosis is poor. Our aim is to describe the outcome and to identify potential prognostic factors.

METHODS

From 1993 to 2005, 7 patients with a malignant triton tumor of the head and neck were treated at our institution. A literature search revealed another 46 published cases. All these cases were analyzed for outcome and prognostic factors.

RESULTS

Patients with primary tumors involving the nose and paranasal sinuses have better, patients involving the neck a poor prognosis. All other locations show an intermediate course. Complete surgical removal is of crucial importance. Additional radiation or chemotherapy show little effect.

CONCLUSION

Location of the primary tumor is a key factor for prognosis. Complete surgical removal is the only treatment associated with survival.

[Malignant triton tumor of the sinonasal tract]

INTRODUCTION

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.

CASE

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.

DISCUSSION

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.

Low-grade malignant Triton tumor of the oral cavity: a case report

Malignant Triton tumor (MTT) is a malignant peripheral nerve sheath tumor showing rhabdomyoblastic differentiation. It is considered a high-grade neoplasm with poor outcome. This report describes an MTT appearing in the oral cavity. On histologic examination the encapsulated lesion was composed of interlacing fascicles of spindle cells and scattered, large, strap-like pleomorphic cells with abundant eosinophilic cytoplasm. No cross striations were seen. Examination of levels through the tissue showed a total of only 4 normal mitoses and no necrosis. Immunohistochemistry demonstrated diffuse S100 positivity in the spindle cells. The large pleomorphic cells were weakly positive for alpha-sarcomeric actin and myoglobin, although variably but strongly positive for desmin. Management involved a small en bloc resection of the maxilla. After 33 months there was no sign of recurrence or distant metastasis. It was concluded that low-grade variants of MTT occur that do not have an aggressive clinical course.

Embryonal rhabdomyosarcoma presenting in an adult: a case report and discussion of immunohistochemical staining

Embryonal rhabdomyosarcoma is the most common soft tissue sarcoma of childhood but is rarely seen in adults. We report an embryonal rhabdomyosarcoma of the cheek in a 21-year-old Filipino man presenting as a rapidly enlarging mass. An incisional biopsy was consistent with embryonal rhabdomyosarcoma. The patient failed to respond to one cycle of chemotherapy after initial diagnosis and workup for metastatic disease. Wide local excision of the tumor was then completed with the use of the Mohs technique to clear the glabrous cutaneous margins during surgery. A Mohs surgeon and dermatopathologist were involved in interpretation of the Mohs sections. Subsequent immunohistochemical staining revealed a poorly differentiated spindled and epithelioid cell tumor, which stained diffusely positive for vimentin, S-100, and MyoD1. Rare rhabdomyoblasts were present and stained positively for desmin, muscle-specific actin, and phosphotungstic acid hematoxylin. The patient subsequently underwent radiation therapy for a total of 6,000 cGy, followed by two cycles of chemotherapy. The patient continues to be disease-free at 22 months after his wide local excision.