Triton Tumor

19-year-old female with a history of neurofibromatosis type I. The patient presented with abdominopelvic pain. Centered low within the abdomen and extending into the pelvis, there is a large solid and cystic lesion with well circumscribed margins and lobular components that are T2/STIR hyperintense and T1-iso- to hypointense. There are several nodular components of the lesion which demonstrate diffusion restriction and very minimal enhancement. There is an additional lesion centered within the left femoral neck region. Following percutaneous biopsy, a diagnosis of Triton tumor was made. Triton tumors represent a form of malignant peripheral nerve sheath differentiation with skeletal muscle differentiation. This subtype accounts for approximately 5% of malignant peripheral nerve sheath tumors and are associated with poorer outcomes than conventional malignant peripheral nerve sheath tumors. Malignant peripheral nerve sheath tumors can develop anywhere in the body but usually along the major nerve roots. Primary tumors most commonly occur in the extremities followed by the trunk and the head and neck region. Tumors in the extremities have better outcomes compared with other sites.