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

Treatment of primary epididymal adenocarcinoma: a case report and review of the literature

BACKGROUND

Epididymal tumors, especially malignant tumors, have low incidence and are rare in our clinical work. However, they may progress quickly and have poor prognosis. For such rare clinical cases with extremely low incidence rates, and as they are prone to misdiagnosis and missed diagnosis and have a very poor prognosis, clinical workers need to pay special attention and consider the possibility of primary epididymal malignant tumors.

CASE REPORT

A 63-year-old Chinese male patient from Asia was admitted due to scrotal pain. Upon examination, an abnormal lesion was found in the right epididymal region. After thorough evaluation, surgical resection was performed, and the postoperative pathological result confirmed the presence of epididymal adenocarcinoma. After further ruling out secondary lesions, primary epididymal adenocarcinoma was considered. Right retroperitoneal lymph node dissection was performed under laparoscopic for treatment, and 1/11 lymph node metastasis was detected after surgery. The patient is currently under close follow-up.

CONCLUSIONS

The number of clinical cases of primary epididymal malignant tumors is very limited, there is currently no standardized diagnosis and treatment process, and there is a lack of systematic evaluation methods regarding the effectiveness of different treatment options such as chemotherapy, radiotherapy, immunotherapy, and targeted therapy. In addition, the outcome is difficult to predict. In this article, we reviewed relevant literature and systematically elaborated on the diagnosis and treatment of epididymal malignant tumors, hoping to provide useful information for relevant experts.

Primary hepatic malignant triton tumor mimicking hepatocellular carcinoma by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging: a case report and literature review

Background

Malignant Triton tumor (MTT) is a relatively rare subtype of malignant peripheral nerve sheath tumor (MPNST) characterized by rhabdomyosarcoma differentiation. There are no distinct features of MTT, and it is easy to misdiagnose preoperatively.

Case presentation

Here, we describe a rare case of primary hepatic MTT in a 56-year-old male who presented with nonspecific abdominal pain for 1 day. Magnetic resonance imaging and abdominal computed tomography revealed an extremely large mass located in the right liver with intratumoral hemorrhage, arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging and the possibility of intrahepatic metastasis. Tumor marker levels revealed only an elevated level of alpha-fetoprotein (AFP: 5304.0 ng/mL). Then, he received transcatheter arterial chemoembolization combined with lenvatinib and pembrolizumab, and he was diagnosed with hepatocellular carcinoma. After 3 months of neoadjuvant therapy, we resected the hepatic cancer and adherent diaphragmatic pleura. MTT was confirmed by postoperative pathology and immunohistochemistry.

Conclusion

Despite the preoperative diagnosis of hepatocellular carcinoma with a rising serum AFP level, typical CT and MRI findings, histopathology assessment showing MPNST with rhabdomyosarcoma differentiation confirms the diagnosis of primary hepatic MTT.

Impact of CT and MRI in the diagnostic workup of malignant triton tumour-a monocentric analysis and review of the literature

OBJECTIVES

Malignant triton tumours (MTTs) are rare but aggressive subtypes of malignant peripheral nerve sheath tumours (MPNSTs) with a high recurrence rate and 5-year survival of 14%. Systematic imaging data on MTTs are scarce and mainly based on single case reports. Therefore, we aimed to identify typical CT and MRI features to improve early diagnosis rates of this uncommon entity.

METHODS

A systematic review on literature published until December 2022 on imaging characteristics of MTTs was performed. Based on that, we conducted a retrospective, monocentric analysis of patients with histopathologically proven MTTs from our department. Explorative data analysis was performed.

RESULTS

Initially, 29 studies on 34 patients (31.42 ± 22.6 years, 12 female) were evaluated: Literature described primary MTTs as huge, lobulated tumours (108 ± 99.3 mm) with central necrosis (56% [19/34]), low T1w (81% [17/21]), high T2w signal (90% [19/21]) and inhomogeneous enhancement on MRI (54% [7/13]). Analysis of 16 patients (48.9 ± 13.8 years; 9 female) from our institution revealed comparable results: primary MTTs showed large, lobulated masses (118 mm ± 64.9) with necrotic areas (92% [11/12]). MRI revealed low T1w (100% [7/7]), high T2w signal (100% [7/7]) and inhomogeneous enhancement (86% [6/7]). Local recurrences and soft-tissue metastases mimicked these features, while nonsoft-tissue metastases appeared unspecific.

CONCLUSIONS

MTTs show characteristic features on CT and MRI. However, these do not allow a reliable differentiation between MTTs and other MPNSTs based on imaging alone. Therefore, additional histopathological analysis is required.

ADVANCES IN KNOWLEDGE

This largest published systematic analysis on MTT imaging revealed typical but unspecific imaging features that do not allow a reliable, imaging-based differentiation between MTTs and other MPNSTs. Hence, additional histopathological analysis remains essential.

Malignant "triton" tumor of the lower extremity with a history of fracture

INTRODUCTION

Malignant triton tumor (MTT) is a rare and aggressive subtype of malignant peripheral nerve sheath tumor consisting of a neurogenic tumor with rhabdomyoblastic differentiation. Only 170 cases have been reported to date, two-thirds occurring in young patients with neurofibromatosis type 1 and the remaining third presenting as a sporadic tumor.

CASE PRESENTATION

We present the case of a 49-year-old man with a sporadic grade 2 MTT of the lower limb which had had a previous tibial fracture. The patient underwent an above-knee amputation. Five months post-operatively metastases were present in the liver and vertebral column causing compression of the spinal cord, so decompressive radiotherapy and palliative chemotherapy were initiated.

CONCLUSION

Due to the precocious spread of the disease, we would suggest that adjuvant chemotherapy be considered for the eradication of micrometastases. To our knowledge, this is only the second reported case of an MTT arising in a site with a history of previous severe trauma.

Liver metastasis 13 years after the resection of a malignant triton tumor originating in the duodenum

This is an additional case report of a malignant triton tumor arising in the duodenum that was removed by pancreatoduodenectomy. Liver and gallbladder dysfunctions were detected in a regular blood examination during a follow-up for hypertension in a 62-year-old woman with a previous surgical history for a malignant Triton tumor in the duodenum 13 years ago. Further examinations revealed a metastatic liver tumor originating from the malignant triton tumor in the duodenum. Since the progression of the liver tumor was detected after radiation therapy, complete resection was performed by right hepatectomy. Curative hepatectomy resulted in disease-free survival for 1 year and 5 months in an extremely rare case of liver metastasis derived from a malignant triton tumor in the duodenum.

Malignant triton tumor of the anterior mediastinum: a rare tumor in a rare location

Malignant triton tumors are an extremely aggressive form of malignant peripheral nerve sheath tumor that display rhabdomyosarcomatous features. While these tumors are extremely rare, they have a much higher incidence in patients with neurofibromatosis-1. We present a case of a 64-year-old male with neurofibromatosis-1 who presented to the hospital with sudden worsening of shortness of breath and dysphagia to solids. Radiological examination revealed a large mass in the anterior mediastinum causing significant narrowing and displacement of the upper trachea and esophagus. Biopsy of the mass, done by interventional radiology, demonstrated features of an MTT. The mass was subsequently resected but without confirmation of tumor-free margins and the patient underwent adjuvant radiation therapy. Repeat radiological examination approximately four months later revealed growing malignancy and new metastases, which eventually contributed to the patient's death seven months after his presentation to the hospital.

[Malignant Triton tumour: A case report]

Malignant Triton tumour (MTT) is a subtype of malignant peripheral nerve sheaths tumour (MPNST) with exclusive heterologous rhabdomyosarcomatous contingent. MTT is rare and of poor prognosis. This entity illustrates the great heterogeneity of MPNST, the diagnosis of which is difficult in the absence of a specific marker, especially in sporadic forms. Although MTT preferentially develop in patients with type 1 neurofibromatosis, sporadic cases may occur. We herein present a case of MTT of the left arm, occurring in a 74-year-old patient, without clinical context of NF1. The fast-growing tumour reached 9.2cm of greater dimension at the time of surgical excision. Histology showed a spindle cell sarcoma with rhabdoid cell areas expressing myogenin. In the absence of neural crest markers expression, the diagnosis of MPNST was based on a significant loss of expression of the histone 3 tri-methylated lysine 27, a classical although not specific epigenetic mark for this sarcoma group, and on the identification of the heterologous rhabdomyosarcomatous contingent, previously described in the context of MTT.

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.

A Case of Retroperitoneal Malignant Triton Tumor in a Nigerian Boy

Malignant peripheral nerve sheath tumor is a rare tumor occurring in 5%–10% of all malignant soft tissues sarcomas and triton tumor arising from neurofibromatosis type 1 (NF-1) is even rarer with associated high rate of mortality. No case of triton tumor has been reported in Nigeria to the best of our knowledge. We seek to report a case of lately detected retroperitoneal triton tumor presenting in a 12-year-old Nigerian child who was brought with bilateral lower limb weaknesses, weight loss, and a right lumbar mass. There were multiple café au lait spots on the body. Abdominal computerized tomographic scan revealed a huge right retroperitoneal mass crossing the midline, compressing adjacent structures with multilevel intraspinal extensions. Core needle biopsy performed and both histology and immunohistochemical studies confirmed the diagnosis, but patient demised in the course of care. The aim is to heighten suspicion of this extremely very rare malignant tumor in children with NF-1.

Insidious malignant triton tumor of the chest wall with late flare-up

Malignant triton tumor is a rare malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Most of these tumors are located in the head, neck, and extremities, and about half of cases are associated with neurofibromatosis type 1 featuring cafe-au-lait spots or cutaneous neurofibromas. We present a 76-year-old man with an insidious chest wall tumor with late progressive painful enlargement and pleural and pulmonary involvement. Complete resection of the affected thoracic wall as well as single separate lesions in the parietal pleura and left upper lung was carried out. The pathological examination confirmed that it was a malignant triton tumor. The patient received adjuvant chemo-radiotherapy but eventually succumbed to disease relapse and distant metastases 6 months after the surgery.

Malignant Triton Tumor (Malignant Peripheral Nerve Sheath Tumor With Rhabdomyoblastic Differentiation) Occurring in a Vascularized Free Flap Reconstruction Graft

Malignant peripheral nerve sheath tumor (MPNST) is a rare form of sarcoma arising from Schwann cells or pluripotent cells of the neural crest. Malignant triton tumor (MTT) is a subtype of MPNST with a component of malignant rhabdomyoblasts in addition to malignant Schwann cells. MPNST and MTT are both aggressive malignancies that most commonly arise from large deep neurofibromas in patients with neurofibromatosis type 1 (NF-1). However, sporadic non-NF-1 cases of MTT have also been reported in the literature. We present a case of a 50-year-old African American male with no stigmata of NF-1 who developed a large mass in a free flap on the right calf. The free flap had been placed by plastic surgery 15 years previously following open right tibial and fibular fractures associated with a large soft tissue defect. Biopsy of the enlarging mass, followed by wide surgical excision, confirmed the pathology to be MTT. Although the development of a high-grade soft tissue sarcoma has been previously reported as a late complication of radiation therapy following free flap reconstructions, we believe this is the first reported case of sarcomatous transformation arising in a vascularized, free muscle transfer.

Modified simultaneous integrated boost radiotherapy for large retroperitoneal malignant tumor: A case report

The current study reports the case of a large retroperitoneal tumor treated with modified simultaneous integrated boost (SIB) radiotherapy. A 45-year-old female presented to the emergency department complaining of left abdominal pain and fever. A computed tomography scan detected a retroperitoneal tumor of 12×16×16 cm, and a biopsy revealed a poorly-differentiated adenocarcinoma. The patient was diagnosed with a large adenocarcinoma originating from the left ureter, with no distant metastasis. Due to the patient's poor physical condition, surgery was not recommended, and the patient was referred to the Department of Radiation Oncology (Yamagata University Hospital, Yamagata, Japan). Modified SIB radiotherapy was administered following the acquisition of written consent from the patient. The total irradiation dose to the center of the tumor and to the surrounding healthy tissue was ∼96 Gy/33 fractions and <60 Gy/33 fractions, respectively. At the end of the radiotherapeutic course, the tumor volume was reduced by ≥80%, and the residual tumor was surgically resected. As a result of the resection, a complete pathological response was confirmed; the patient has been recurrence-free for >3 years with no complications. Modified SIB radiotherapy may be safely administered, with favorable outcomes. Complete recovery can be achieved with this technique, even in a patient with a large radioresistant tumor.

Malignant Triton Tumors in Sisters with Clinical Neurofibromatosis Type 1

Malignant triton tumors (MTTs) are rare and aggressive sarcomas categorized as a subgroup of malignant peripheral nerve sheath tumors (MPNSTs). MTTs arise from Schwann cells of peripheral nerves or existing neurofibromas and have elements of rhabdomyoblastic differentiation. We report the occurrence of MTTs in two sisters. The first patient is a 36-year-old female who presented with left sided chest wall swelling. She also had clinical features consistent with neurofibromatosis type 1 (NF-1). Debulking of the mass showed high-grade malignant peripheral nerve sheath tumor with skeletal muscle differentiation (MTT). The patient was treated with ifosfamide and adriamycin along with radiation. Four years after treatment, she still has no evidence of disease recurrence. Her sister subsequently presented to us at the age of 42 with left sided lateral chest wall pain. Imaging showed a multicompartmental retroperitoneal cystic mass with left psoas involvement. The tumor was resected and, similarly to her sister, it showed high-grade malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation (MTT). The patient was started on chemotherapy and radiation as described above.

Malignant Triton Tumor of the Sciatic Nerve as a Secondary Malignancy after Extended Field Radiotherapy and Chemotherapy of Hodgkin's Disease

Late effects of therapy for Hodgkin's disease include secondary malignancies like leukemia, lymphoma or solid tumors developing after long periods of latency. Ionizing radiation often causes the last group. The highest risks have been described for induced breast and lung cancers. We are the first to report a malignant triton tumor (MTT) as a secondary malignancy after radiotherapy and chemotherapy for Hodgkin's lymphoma. MTT is a very rare subtype of malignant peripheral nerve sheath tumors with rhabdomyoblastic differentiation and an aggressive course of disease.