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

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Case report: Concurrent malignant triton tumor and relapsed pituitary adenoma in the sellar region

Malignant triton tumor (MTT) is a rare kind of malignant peripheral nerve sheath tumors, histologically characterized by rhabdomyoblastic differentiation. There are limited reports of MTT occurring in the intracranial area. The treatment modality consisting of total surgical resection plus post-operative radiotherapy is generally accepted. However, even with optimal treatment, most patients will die within a few months. We report a 71-year-old man with a history of pituitary adenoma, who underwent surgical treatment and postoperative gamma knife therapy. Magnetic resonance imaging (MRI) of the brain revealed a mass with two distinctive components in the sellar area. Postoperative pathology found that the lesion consisted of a MTT and a relapsed pituitary adenoma. The present case is the first report of MTT that occurred in the sellar area. It is also the first case of intracranial MTT with other concurrent tumors (relapsed pituitary tumors). Meanwhile, this case has a clear history of radiation therapy, suggesting that the occurrence of MTT may be related to radiation.

Malignant triton tumor of the rectum - A case report and review of the literature

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Malignant triton tumor are rare tumors causing ileus.

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Multimodal treatment with repetitive surgical resection can improve outcome in MTT.

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MTT shows a high rate of local recurrence.

Introduction

Malignant triton tumors (MTT) are rare but highly aggressive tumors that originate from the Schwann cells. These tumors can occur in any part of the body, mostly present late and carry poor prognosis.

Presentation of case

We present a 24-year-old man with a rectal MTT causing non-specific abdominal pain and recurring ileus. The MRI showed a rectal mass near the urinary bladder with compression on the seminal vesical. A complete surgical resection of the tumor was performed. The immunohistological report confirmed a rectal MTT. Because of persistent ileus during the post-operative palliative chemotherapy, another tumor debulking was performed. The patient died 9 months after the diagnosis of MTT due to local recurrence under chemotherapy.

Discussion and conclusion

MTTs are uncommon tumors in young age with high morbidity and mortality because of local recurrence also after complete resection.

Mediastinal malignant triton tumor: A rare case series and review of literature

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Malignant triton tumor (MTT) is extremely rare subset of malignant peripheral nerve sheath tumor (MPNST) which accounts for < 10% of all MPNST.

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Due to their aggressive biological behavior prognosis is very poor.

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To date in medical literature only 12 cases of malignant triton tumor has been reported.

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We report series of three mediastinal malignant triton.

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Managed with radical surgical resection and neoadjuvent chemotherapy &radiotherapy.

Introduction

In 1938, the Malignant Triton Tumor (MTT) was first explained by Mason.

Case presentation

Case 1: A man aged 28 years presented with chest pain and difficulty in breathing since last five months, there was no history of cough fever or night sweats. Clinical examination was unremarkable. His routine hematological tests including tumor markers were within normal range, testicular ultrasound was normal. CT scan of thorax revealed a mass in the anterior mediastinum. CT guided biopsy revealed a malignant triton tumor.

Case 2: A 30 years old man, nonsmoker presented with history of chest tightness and feeling pressure while kneeling down since last 3 months, otherwise fit and healthy. His routine hematological investigations including tumor markers were within normal range. A CT scan of thorax revealed a large mass in the right posterior mediastinum. CT guided biopsy showed malignant triton tumor.

Case 3: A man aged 28 years presented with chest pain and difficulty in breathing since last five months, there was no history of cough fever or night sweats. Clinical examination was unremarkable. His routine hematological tests including tumor markers were within normal range, testicular ultrasound was normal. CT scan of thorax revealed a mass in the anterior mediastinum. CT guided biopsy revealed a malignant triton tumor.

Discussion

Malignant peripheral nerve sheath tumors (MPNST) are uncommon sarcomatous tumors that are believed to be derived from Schwann cell or neighboring cells with perineurial differentiation. MTT is rarely reported in mediastinum, lung and heart (<10%) To the best of our knowledge, only few cases of MTT in the mediastinum have been reported in English literature, including, four were reported in the anterior mediastinum, three in the posterior mediastinum, one in the middle mediastinum and one between the ascending aorta and the main pulmonary artery. Most of the patients were young adults. We report three cases of rare mediastinal malignant triton tumors. They have been treated with palliative surgery/radical surgery +/− adjuvant therapy. The prognosis varied from a 3 month overall survival time to being alive at a 53 month follow-up period.

Conclusion

In conclusion we report three rare cases of mediastinal malignant triton tumor treated with radical surgical resection and post-operative radiotherapy, one patient developed lung metastasis, and two had late local recurrence. The malignant triton tumor is a lethal neoplasm which carries very poor prognosis particularly when they occur in the mediastinum because it’s very difficult to obtain wider tumor free margin due to the nature of location site.

Biphenotypic sinonasal sarcoma: demographics, clinicopathological characteristics, molecular features, and prognosis of a recently described entity

Biphenotypic sinonasal sarcoma (BSNS) is a recently recognized type of sarcoma arising exclusively in the sinonasal tract displaying unique clinical course, histopathology, and genetics. Due to its rarity, only case series and case reports are available. In order to provide an overview of the current understanding of this disease, we present a comprehensive review of the literature and present three previously unreported cases of BSNS. A total of 55 genetically characterized and 41 cases without molecular data were identified in the literature. Two-thirds of patients were female and the peak incidence was in the fifth decade. Fatal outcome was rare (two cases with intracranial extension) and local recurrence occurred in 31.6%, all occurring within 5 years after initial treatment. Histologically, BSNS is highly cellular in the majority of cases and composed of fascicles of spindle cells, with entrapped hyperplastic surface epithelium being a frequent finding. The immunohistochemical profile is characteristic due to the biphasic nature of this lesion, with shared features of both myogenic and neural origin. Rhabdomyoblastic differentiation is apparent in a subset of cases. The most common genetic event is the PAX3-MAML3 fusion (58.6%) but isolated PAX3 rearrangement (19.2%), absence of rearrangements (9.1%), PAX3-FOXO1 (8.1%), PAX3-NCOA1 (4%), and isolated MAML3 rearrangement (2%) have also been reported. In conclusion, the recognition of BSNS is crucial due to its relatively indolent clinical course. A selected immunohistochemical panel and/or molecular confirmation can be used to aid in appropriate diagnosis and consequently in prognostication and to avoid overtreatment with chemotherapy regimens used in its mimics.

RREB1-MKL2 fusion in biphenotypic "oropharyngeal" sarcoma: New entity or part of the spectrum of biphenotypic sinonasal sarcomas?

An increasing number of sarcomas displaying a primitive, monomorphic spindle cell phenotype have been shown to harbor recurrent gene fusions, including biphenotypic sinonasal sarcoma (SNS). Occurring in the sinonasal area of middle-aged patients, SNS is a locally aggressive tumor harboring in 90% of cases recurrent gene fusions involving the PAX3 gene, in which the chimeric transcription factor induces an aberrant dual myogenic and neural phenotype. Here, we report an unusual oropharyngeal monomorphic spindle cell sarcoma in a 53-year-old man that revealed a novel RREB1-MKL2 gene fusion by RNA sequencing with the Illumina TruSight RNA Fusion Panel. The gene fusion was validated by RT-PCR. Although the tumor location is unusual (but head and neck seated), most of the other clinical, morphologic, immunophenotypic (focal combined expression of S100 protein, SMA, desmin, and myogenin) and oncogenic data suggest that this biphenotypic "oropharyngeal" sarcoma is closely related to the biphenotypic SNS spectrum. Notably, the RREB1-MKL2 chimeric transcription factor encoded by this fusion gene produced an increase in MKL2 expression, which regulates both neural and myogenic differentiation, mimicking the crucial role of PAX3 reported in SNS oncogenesis. NGS and especially RNA sequencing may be used to identify new candidate fusion oncogenes in soft tissue tumors, which would help in updating the existing classification. In turn, this would lead to better therapeutic management of patients.

A case of recurrent malignant triton tumor successfully treated with radiotherapy

A 15-year-old female was previously admitted to another hospital because of painless swelling of the lateral right nasal ala for 2 months. Magnetic resonance imaging revealed an expansive enhancing lesion in close proximity to the anterior surface of the right maxillary sinus and lateral wall of the right nasal cavity. Tumor extirpation was performed via the supragingival transantral approach under general anesthesia. Histopathological study revealed a malignant triton tumor (MTT) arising from the nasal vestibule. The patient was referred to our department for consultation regarding additional treatment. Because the surgical margin was positive and MTT has high malignant potential, we recommended expansion re-surgical treatment following immediate free-flap reconstruction and postoperative radiotherapy, but family consent was not obtained. Tumor regrowth was noted 1 month after her first visit to our department. The patient and her family accepted radiotherapy instead of surgical treatment. Complete remission was achieved by radiotherapy alone. No local recurrence or distant metastasis was observed for 30 months after radiotherapy. The conventional mode of treatment for MTT is radical excision followed by high-dose radiotherapy. However, this case is remarkable because our patient experienced complete remission by simple radiotherapy.

Novel PAX3-NCOA1 Fusions in Biphenotypic Sinonasal Sarcoma With Focal Rhabdomyoblastic Differentiation

Sarcomas arising in the sinonasal region are uncommon and encompass a wide variety of tumor types, including the newly described biphenotypic sinonasal sarcoma (BSNS), which is characterized by a monomorphic spindle cell proliferation with dual neural and myogenic phenotypes. Most BSNSs harbor a pathognomonic PAX3-MAML3 fusion driven by t(2;4)(q35;q31.1), whereas the alternative fusion partner gene remains unidentified in a subset of PAX3-rearranged cases. As NCOA1 on 2p23 is a known partner in PAX3-related fusions in other tumor types (ie, alveolar rhabdomyosarcoma), we investigated its status by fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction assays in 2 BSNS cases showing only PAX3 gene rearrangements. Novel PAX3-NCOA1 fusions were identified in these 2 index cases showing an inv(2)(q35p23) by FISH and confirmed by reverse transcription polymerase chain reaction. Five additional BSNS cases with typical morphology were studied by FISH, revealing a PAX3-MAML3 fusion in 4 cases and only PAX3 rearrangement in the remaining case without abnormalities in MAML3 or NCOA1 gene. Except for 1 case with surface ulceration, all other tumors lacked increased mitotic activity or necrosis, and all cases immunohistochemically coexpressed S100 protein and actin, but lacked SOX10 reactivity. Interestingly, the 2 PAX3-NCOA1-positive cases showed desmin reactivity and displayed a small component of rhabdomyoblastic cells, which were not seen in the more common PAX3-MAML3 fusion cases. In conclusion, we report a novel PAX3-NCOA1 fusion in BSNS, which appears to be associated with focal rhabdomyoblastic differentiation and should be distinguished from PAX3-NCOA1-positive alveolar rhabdomyosarcoma or malignant Triton tumor. SOX10 immunohistochemistry is a useful marker in distinguishing BSNS from peripheral nerve sheath tumors.

Newly Described Tumor Entities in Sinonasal Tract Pathology

Surgical pathology of the sinonasal tract (nasal cavity and paranasal sinuses) is extremely challenging due in part to the tremendous diversity of tumor types that may arise in this region. Compounding the difficulty, a number of new sinonasal tumor entities have been recently described, and pathologists may not yet be familiar with these neoplasms. This manuscript will review the clinicopathologic features of some of the newly described sinonasal tumor types: NUT midline carcinoma, HPV-related carcinoma with adenoid cystic-like features, SMARCB1 (INI-1) deficient sinonasal carcinoma, biphenotypic sinonasal sarcoma, and renal cell-like adenocarcinoma.

Analysis of clinical features and prognosis of malignant triton tumor: A report of two cases and literature review

Malignant triton tumor (MTT) is a malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. The prognosis of patients is poor, and due to its rarity, large case studies are lacking. The aim of this study is to describe the clinical features and identify potential prognostic factors. Two patients with MTT in the head and neck treated at our department are reported. A literature search revealed another 198 published cases. All of these cases then went through a retrospective analysis. The ratio of male-to-female incidence was 1.5:1, and the median age at diagnosis was 29 years. In 41.7% of cases it occurred in patients with neurofibromatosis type 1. The five-year survival of MTT was found to be just 35%. Cox proportional hazards analysis revealed that complete resection (hazard ratio, 0.396; P=0.032) and metastases (hazard ratio, 3.188; P=0.004) were associated with mortality, indicating that complete resection may lead to a longer life span, and that the existence of metastasis suggested a worse prognosis for patients with MTT.

Rhabdomyoblastic Differentiation in Head and Neck Malignancies Other Than Rhabdomyosarcoma

Rhabdomyosarcoma is a relatively common soft tissue sarcoma that frequently affects children and adolescents and may involve the head and neck. Rhabdomyosarcoma is defined by skeletal muscle differentiation which can be suggested by routine histology and confirmed by immunohistochemistry for the skeletal muscle-specific markers myogenin or myoD1. At the same time, it must be remembered that when it comes to head and neck malignancies, skeletal muscle differentiation is not limited to rhabdomyosarcoma. A lack of awareness of this phenomenon could lead to misdiagnosis and, subsequently, inappropriate therapeutic interventions. This review focuses on malignant neoplasms of the head and neck other than rhabdomyosarcoma that may exhibit rhabdomyoblastic differentiation, with an emphasis on strategies to resolve the diagnostic dilemmas these tumors may present. Axiomatically, no primary central nervous system tumors will be discussed.

Malignant triton tumor of the cervical spine: report of one case and review of the literature

Malignant triton tumor (MTT) is a highly aggressive malignant neoplasm, classified as a variant of malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. MTT is rarely reported in children, and its true prevalence may be underestimated. We herein report such a case in an 8-year-old boy who presented with a mass over the trapezius muscle. He was previously diagnosed with neurofibromatosis in the same area. Four years later, a follow-up magnetic resonance imaging revealed an intradural tumor recurrence at the level of C1-C7. An immunohistochemical test result was positive for S-100 protein and desmin, which confirmed the diagnosis. The patient outcome was fatal despite multimodal therapy. The possibility of this rare but devastating tumor must always be considered when patients present with new compressive spinal symptoms.

Low-grade malignant triton tumor of the neck: a case report and review of the literature

Rhabdomyoblastic differentiation in a malignant peripheral nerve sheath tumor (MPNST) is termed malignant triton tumor (MTT), a rare neoplasm that poses a diagnostic dilemma in the differential diagnosis of neck masses and portends poor prognosis. We report a sporadic case of MTT of the neck in a 23-year-old female. We present the pathological findings. Immunohistochemistry confirmed the neurogenic origin with S-100 expression and the rhabdomyoblastic differentiation with desmin and vimentin positivity. Radical surgical excision was done. After 4 years there were no signs of recurrence or distant metastasis. The clinical, microscopic, and long-term follow-up of this case are consistent with those of a low-grade malignancy.

Malignant triton tumour of the sinonasal tract: Case report and literature review

INTRODUCTION

The objective is to report a rare tumour of the sinonasal tract and conduct a literature review. Malignant triton tumour is a subtype of malignant schwannoma with rhabdomyoblastic differentiation. It is a very rare tumour, with only 15 reported cases involving the sinonasal region.

PRESENTATION OF CASE

Forty-seven years old female presented with a right-sided epistaxis, progressive right sided nasal obstruction and anosmia and a visible mass in the right nasal cavity. Imaging studies showed a mass extending from the piriform aperture to the nasopharynx in contact with the dura and the orbital content. The mass was biopsied and the result was consistent with malignant triton tumour. The patient refused the surgery at first so chemotherapy with MAID protocol was started. After the fourth course of chemotherapy the treatment was stopped due to patient intolerance and a thrombosis of the jugular vein. Patient then underwent surgery with frontal craniotomy and dural excision, endoscopic control was done at the end to insure a complete removal. The patient received Radiotherapy in the postoperative period (56 Greys). At 5 years of follow up the patient is doing fine with no signs of recurrence and normal ophthalmological findings.

DISCUSSION

Sixteen cases, including our case, have been reported to date in the literature. The mean age at presentation is 61 years. None of cases were associated with neurofibromatosis type 1. Eight patients were reported to be alive 5 years post-treatment, and 2 patients were reported to have died of the disease. The prognosis for triton tumours in the sinonasal tract is better than that for triton tumours in other locations.

CONCLUSION

Malignant triton tumour is a rare malignancy of the sinonasal tract. Otolaryngologists should be aware of this disease. The optimal treatment should include radical resection of the tumour.

Malignant triton tumor of the retroperitoneum: a case report and review of the literature

Background

Malignant triton tumors are relatively rare and highly aggressive tumors in which malignant schwannoma cells coexist with rhabdomyoblasts. Their occurrence in the retroperitoneum is uncommon and has been rarely reported.

Case presentation

We present the case of a patient with a retroperitoneal malignant triton tumor. A 32-year-old male was referred with epigastric pain and an abdominal mass. Computed tomography revealed a huge soft tissue retroperitoneal mass that involved adjacent organs and vessels. Complete resection was undertaken. Pathological examination confirmed the presence of a malignant triton tumor. The patient died two and a half months after surgery, as a result of local recurrence.

Conclusion

Malignant triton tumors are uncommon sarcomas that are associated with a high incidence of developing local recurrence and distant metastases. Immunohistochemical staining showing nerve sheath differentiation with rhabdomyoblastic cells confirms the diagnosis. Complete excision of the tumor is the most effective treatment strategy for these retroperitoneal tumors.