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.