Malignant triton tumor (MTT) is a very infrequent variant of the malignant peripheral nerve sheath tumor (MPNST) with rhabdomyoblastic differentiation. Up to 70% of cases are diagnosed in patients with neurofibromatosis type 1 (NF1). It is a highly aggressive pathology with early relapses occurring in up to 50% of patients. Despite multimodal treatment the prognosis is poor, with long term survival rates not exceeding 15%. We present the case of an adolescent male with known NF1 diagnosed with an aggressive retroperitoneal MTT and disseminated pulmonary disease.