Usefulness of (18)F-FDG-PET/CT in Evaluating a Brainstem Glioma in an Adult Patient with Neurofibromatosis Type 1.

Abstract

We describe a case of a brainstem glioma (BSG) occurred in an adult patient with neurofibromatosis type 1 (NF1) and evaluated by Flourine-18-Fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT). A 32-year-old male patient with NF1 underwent brain magnetic resonance imaging (MRI) for the onset of diplopia, facial paresis and cerebellar signs and symptoms. MRI showed a brainstem lesion compatible with BSG. Biopsy was not performed. 18F-FDG-PET/CT demonstrated intense 18F-FDG uptake in the brainstem lesion, suggesting an aggressive neoplasm. The patient was referred to radiotherapy but he developed rapid disease progression. In this case, 18F-FDG-PET/CT provided useful information about this rare NF1-associated tumor (Figs. ​(Figs.11 and ​and22). Fig. 1 We report the case of a 32-year-old male patient with neurofibromatosis type 1 (NF1) affected by a brainstem glioma (BSG). The patient underwent brain magnetic resonance imaging (MRI) for the onset of diplopia, facial paresis and cerebellar signs and ... Fig. 2 The biopsy of the lesion was not performed and the patient underwent 18F-FDG-PET/CT for the metabolic characterization of this brainstem lesion. Before 18F-FDG injection, the patient had fasted for at least 6 h; at the time of the radiopharmaceutical ... Subsequently, the patient was referred to radiotherapy, but he developed rapid disease progression and died 3 months later. NF-1 is an autosomal dominant disorder characterized by multiple cafe-au-lait spots, axillary and inguinal freckling, multiple cutaneous neurofibromas, and iris Lisch nodules [1]. NF-1 is also characterized by low-grade tumors of the central and peripheral nervous system. There is also an increased risk of developing malignant tumors such as malignant peripheral nerve sheath tumors or central nervous system high-grade gliomas [1, 2]. NF1-associated BSGs are less common than NF1-associated optic gliomas (OGs) and seem to represent a particular entity which tend, as a whole, to have a more favorable prognosis and a more indolent course than BSGs in patients without NF1 [3–5]; nevertheless, some NF1-associted BSG may rapidly progress [4]. 18F-FDG-PET/CT has demonstrated to provide useful information to the surveillance of OGs in children with NF1, particularly to identify progressive, symptomatic tumors [6–8]. To the best of our knowledge, there are no data about the usefulness of 18F-FDG-PET/CT in adult patients with NF1-associated BSG. In our case, 18F-FDG-PET/CT has been useful in evaluating this rare NF1-associated tumor.