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

Malignant triton tumor in the abdominal wall: A case report

BACKGROUND

Malignant triton tumors (MTTs) comprise a subgroup of malignant peripheral nerve sheath tumors (MPNSTs) that exhibits rhabdomyosarcomatous differentiation and follow an aggressive course. MTTs are primarily located along peripheral nerves. Cases of MTTs in the abdominal wall have not been reported. MTT has a poorer prognosis than classic MPNSTs, and accurate diagnosis necessitates a keen understanding of the clinical history and knowledge of its differential diagnosis intricacies. Treatment for MTTs mirrors that for MPNSTs and is predominantly surgical.

CASE SUMMARY

A 49-year-old woman presented with a subcutaneous mass in her lower abdominal wall and a pre-existing surgical scar that had grown slowly over 3-4 months before the consultation. She had previously undergone radical hysterectomy and concurrent chemo-radiotherapy for cervical cancer approximately 5 years prior to the consultation. Abdominal computed tomography (CT) showed a 1.3 cm midline mass in the lower abdomen with infiltration into the rectus abdominis muscle. There was no sign of metastasis (T1N0M0). An incisional biopsy identified sporadic MTT of the lower abdomen. A comprehensive surgical excision with a 3 cm margin inclusive of the peritoneum was executed. Subsequently, the general surgeon utilized an approach akin to the open peritoneal onlay mesh technique. The patient underwent additional treatment with an excision shaped as a mini-abdominoplasty for the skin defect. No complications arose, and annual follow-up CTs did not show signs of recurrence or metastasis.

CONCLUSION

An abdominal MTT was efficaciously treated with extensive excision and abdominal wall reconstruction, eliminating the need for postoperative radiotherapy.

Malignant triton tumor of the duodenum: report of a case

We report a case of malignant triton tumor of the duodenum, which is extremely rare. A submucosal malignant tumor was detected in the duodenum of a 49-year-old woman. The tumor was completely resected by performing pancreaticoduodenectomy. Pathological examination revealed that the lesion was a malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation, i.e., a malignant triton tumor. Long-term survival has been achieved with no recurrence at 8.5 years after surgery.

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.

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.