Fluorodeoxyglucose and methionine uptake in Lhermitte-Duclos disease: case report

Lhermitte-Duclos disease (LDD) represents a focally indolent dysplastic growth of the cerebellar cortex. The 106 cases reported previously in the literature show an extremely slow evolution, and the operative indications and techniques for this disease entity are still controversial. The authors present the first case of LDD studied with positron emission tomography using the labeled tracers [(18)F]2-fluoro-2-deoxy-d-glucose ([(18)F]FDG) and (11)C-labeled methionine ([(11)C]Met) to study the glucose and protein metabolism of the lesion.

A 40-year-old woman suddenly became unconscious then completely recovered 5 minutes later. Magnetic resonance imaging of her brain showed a well-delineated 10 x 5-cm abnormal area with enlarged cerebellar folia, which led to the diagnosis of LDD.

On positron emission tomographic scans, [(18)F]FDG and [(11)C]Met uptake in the normal cerebral and cerebellar cortex appeared higher than normal, reaching levels found in patients with primary malignant brain tumors. Moreover, the uptake of both tracers was heterogeneous, in contrast to the homogeneous uptake visualized on magnetic resonance imaging scans. The areas of greatest [(11)C]Met and [(18)F]FDG uptake were discordant. Some areas of greater than normal [(18)F]FDG uptake corresponded to areas of moderate or low [(11)C]Met uptake. Because of the important mass effect in the posterior fossa, total surgical resection was performed. A histological examination confirmed the diagnosis of LDD.

This first reported metabolic study of LDD supports the view that LDD is an active and evolving disease. These data should prompt reevaluation of the indications for surgery in patients with this disease as well as the timing of surgery.