High F-18 FDG uptake in a low-grade supratentorial ganglioma: a positron emission tomography case report.
OBJECTIVE
Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (F-18 FDG) is used for the noninvasive monitoring and grading of primary brain tumors. Here the FDG uptake is positively correlated with the malignant extent of the lesion and thereby negatively correlated with patient survival. Little is known about the FDG PET features of primary brain tumors in children, such as mixed neuronal-glial tumors.


METHODS
The authors describe a 13-year-old boy who had partial complex seizures since early childhood caused by a brain tumor in the left temporal lobe.


RESULTS
Magnetic resonance and computed tomographic examinations yielded uncharacteristic results: mixed density, marked calcifications, little contrast enhancement, a nearly absent mass effect, and no edema. The FDG PET scan revealed a large hypermetabolic tumor, with a tumor: contralateral gray matter FDG uptake ratio of 1.45. In contrast to this intense hypermetabolism, the pathologic analysis after gross total resection revealed a low-grade ganglioglioma (WHO grade 1), which is usually associated with an excellent prognosis.


CONCLUSIONS
Mixed neuronal-glial tumors such as gangliogliomas must be considered in making differential diagnoses by judging hypermetabolic FDG PET scans in young patients with brain tumors in the presence of uncharacteristic imaging features.
Meyer
P T
PT
Department of Nuclear Medicine, Aachen University of Technology, Germany. philipptobias.meyer@post.rwth-aachen.de
Spetzger
U
U
Mueller
H D
HD
Zeggel
T
T
Sabri
O
O
Schreckenberger
M
M
D000293:Adolescent; D019788:Fluorodeoxyglucose F18; D018303:Ganglioglioma / Q000000981:diagnostic imaging* / Q000473:pathology; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009457:Neuroglia / Q000473:pathology; D019275:Radiopharmaceuticals; D015173:Supratentorial Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose