Usefulness of 18F-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 ( 18 F-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. 18 F-FDG-PET/CT demonstrated intense 18 F-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, 18 F-FDG-PET/CT provided useful information about this rare NF1-associated tumor ( Figs. 1 and 2).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 café-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 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 symptoms. Coronal (a, b) and axial (c, d) enhanced T1-weighted (a, c) and T2-weighted (b, d) MR images showed the presence of a pontine-based infiltrative lesion (arrows), which presented inhomogenous signal intensity on both T1-weighted and T2-weighted images for the coexistence of isointense and hyperintense areas. These MRI findings were suggestive of a BSG

Brainstem Glioma in Adults

“…MR spectroscopy can be a useful aid for diagnosis, as elevation of the choline/NAA ratio is often detectable, with one analysis of adult brainstem gliomas showing this finding in 100% of cases analyzed ( 3 ). FDG–PET may also be helpful in differentiating aggressive lesions from indolent ones ( 6 ).…”