Background: Malignant triton tumor (MTT) is a rare subtype of malignant peripheral nerve sheath tumor with additional rhabdomyolysis differentiation that shows rapid progression and poor clinical outcomes. Case Report: We report the case of an adult male with a metastatic MTT. Despite extensive counseling, the patient initially refused recommended treatment. Upon disease progression, the patient was admitted to our institution and multiple distant organ metastases were found. The patient underwent an above-knee amputation followed by palliative chemotherapy. The patient died a few months later due to rapid disease progression. Conclusion: To our knowledge, this is the first report of a case of MTT with multiple splenic metastases. We also describe the first finding of a frame-shift mutation in the tuberous sclerosis complex 2 (TSC2) gene in a patient with MTT. Because of limited clinical experience and the lack of clinical trials, the effects of chemotherapy and radiation therapy for MTT remain controversial. However, given the aggressive nature of these tumors and the tendency for early recurrence and metastasis, prompt diagnosis and early surgical treatment are crucial for the best outcomes.