Plurifocal malignant peripheral nerve sheath tumor demonstrated by 18F-fluorodeoxyglucose positron emission tomography/computed tomography.

Malignant peripheral nerve sheath tumors (MPNSTs) are sarcomas that derive from peripheral nerves or from cells associated with the nerve sheath. Magnetic resonance imaging is the main diagnostic imaging modality for evaluating MPNSTs. Computed tomography (CT) of the chest is the main imaging modality used to screen for distant disease, and bone scanning is considered useful for identifying selected metastases. Fluorodeoxyglucose positron emission tomography (FDG-PET) has been useful for differentiating malignant nerve sheath tumors from benign lesions and appears to be able to forecast prognosis. We report a case of a patient with neurofibromatosis 1 (NF1) with a histological diagnosis of MPNST, which was diagnosed by biopsy of a posterior right thigh mass examined by (18)F-FDG-PET/CT.