Lhermitte-Duclos disease presenting with positron emission tomography-magnetic resonance fusion imaging: a case report

Abstract

Introduction: Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life.

Case presentation: We report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease.

Conclusions: Our case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.

Figure 1

Axial positron emission tomography view. (a) Intense glucose metabolism in the left hemisphere of the cerebellum, corresponding to a hypointense and slightly enhancing area with (b) maximum diameter of 5 cm in axial T1-weighted post contrast view. (c) Axial T2-weighted fluid-attenuated inversion recovery images show the characteristic features of Lhermitte-Duclos disease: striations representing the folia of the cerebellum in association with hydrocephalus and dislocation of the fourth ventricle. (d) Axial fused positron emission tomography-magnetic resonance imaging views show the lesion with increased metabolism and intensity signal similar to that of normal grey matter.