Primary meningeal melanomatosis is a rare, aggressive variant of primary malignant melanoma of the central nervous system, which arises from melanocytes within the leptomeninges and carries a poor prognosis. We report a case of primary meningeal melanomatosis in a 17-year-old man, which was diagnosed with 18F-fluorodeoxyglucose (F-18 FDG) PET/CT, and post hoc F-18 FDG PET/MRI fusion images. Whole-body F-18 FDG PET/CT was helpful in ruling out the extracranial origin of melanoma lesions, and in assessing the therapeutic response. Post hoc PET/MRI fusion images facilitated the correlation between PET and MRI images and demonstrated the hypermetabolic lesions more accurately than the unenhanced PET/CT images. Whole body F-18 FDG PET/CT and post hoc PET/MRI images might help clinicians determine the best therapeutic strategy for patients with primary meningeal melanomatosis.
Adolescent ; Brain Neoplasms/*diagnosis/radionuclide imaging ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; *Magnetic Resonance Imaging ; Male ; Melanoma/*diagnosis/radionuclide imaging ; Meningeal Neoplasms/*diagnosis/radionuclide imaging ; *Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/diagnostic use ; Whole Body Imaging