Printer Friendly

Dysplastic cerebellar gangliocytoma lhermitte-duclos disease imaging and magnetic resonance spectroscopy.

INTRODUCTION

Lhermitte-Duclos disease (LDD), also known as dysplastic cerebellar gangliocytoma, is a rare, benign, slow-growing, unilateral mass of the cerebellar cortex. Although this lesion was first described in 1920, debate continues as to whether LDD represents a hamartoma, malformation, or a neoplasm. (1,2) The LDD tumor is composed of hypertrophic granular cells, but the degree of differentiation of these granular cells is variable. (2,3) Although most cases of LDD are sporadic, it is closely associated with the autosomal-dominant Cowden Syndrome (multiple-hamartoma-neoplasm syndrome), with adult onset of LDD considered as a phenol variant of Cowden Syndrome (11) and with mutations of the PTEN gene. (4) Typically, patients with LDD can present in the third or fourth decade with clinical signs of cerebellar dysfunction, increased intracranial pressure, cranial nerve palsies, and obstructive hydrocephalus caused by the mass lesion. (2) Patients presenting with LDD may have other associated signs, including polydactyly, hemangiomas, and skull defects. (2) In addition, patients may present with signs of Cowden Syndrome: trichilemmomas, papillomatous papules, acral keratoses, lipomas, neuromas, hemangiomas, scrotal tongue, macrocephaly, breast adenomas and fibrocystic breast disease, thyroid adenomas, and uterine leiomyomas. (5)

CASE REPORT

A 71-year-old man presented to Tulane Medical Center with a history of unsteady gait for two weeks and a fall on the previous day, during which he hit his head. His medical history was positive only for diabetes mellitus, hypertension, and cardiac arrhythmia. He did not report any relevant family history. On neurologic exam, reflexes were normal at 2+, except for 1+ Achilles tendon reflexes bilaterally. Finger-to-nose testing was normal using both upper extremities. Heel-to-shin testing revealed slight ataxia on the right but was found to be normal on the left. Gait testing was remarkable with mild right leg circumduction during ambulation. Otherwise, the patient had no signs of CNS lesions, such as cranial nerve palsy, aphasia, or any other focal neurologic deficits.

Upon presentation, the patient underwent computed tomographic (CT) evaluation for possible intracranial trauma versus cerebrovascular accident. His initial CT scan was performed without contrast and revealed a hypodensity in the right cerebellar hemisphere measuring 3.2 x 2.9 cm with a striated pattern abutting the tentorium with small linear areas of hyperattenuation that were considered to reflect traumatic hemorrhages or calcifications.

A subsequent magnetic resonance (MR) evaluation was performed with and without contrast to clarify the findings on CT. MR (Figure 1) demonstrated a heterogeneously hyperintense lesion on DWI without restriction in the superior portion of the right cerebellar hemisphere measuring 4.6 x 2.7 x 2.2 cm. The lesion demonstrated heterogeneous, somewhat striated pattern of T2 hyperintensity and T1 hypointensity, with mixed signal intensity on FLAIR sequences. Gross hyperintensity and punctate hypointensity were seen on gradient echo, representing calcification. The lesion caused mass effect, with effacement of the superior fourth ventricle. Based on the MR findings, the differential included Lhermitte-Duclos, low-grade glioma, epidermoid tumor, and hypovascular meningioma.

A correlative proton MR Spectroscopy (1H MRS) exam was performed on the abnormal area in the right superior cerebellar hemisphere using both short and long echo times (TE) of 144 and 35 ms, respectively (Figure 2). (6) The lesion was compared with normal comparable tissue in the left hemisphere. (7) Within the lesion, there was maintenance of N-acetyl-aspartate (NAA), choline (Cho) and myo-inositol (MI), as well as maintenance of the creatine/choline ratio (Cr/Cho). Abnormal elevated lactate was demonstrated with both TE times and was most likely due to increased glucose metabolism. (8)

[FIGURE 1 OMITTED]

DISCUSSION

MRS can be a valuable tool in the analysis of intracranial lesions, allowing non-invasive assessment of the metabolic characteristics of abnormal tissue. Proton magnetic resonance spectroscopy (1H MRS) is useful in analyzing the central nervous system (CNS), due to the high hydrogen concentration in brain tissue. (9) In MR spectroscopy, varying amounts of metabolite are displayed as peaks on a spectral graph. The greater the area under the curve, the larger the amount of metabolite is present in the sample. (10) In order to obtain this spectrum, free induction decay (FID) signal is acquired following the application of radio frequency (RF) pulse. The FID signal is analyzed and converted to a spectrum of unique resonance frequencies corresponding to different metabolites. (10,11) These unique resonance frequencies are determined by the chemical shifts of the protons present in each compound. Using this method, MRS reveals the relative concentrations of several key products of brain metabolism, such as N-acetyl aspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (MI), and lactate, among others. (6) Comparing metabolites to the normal tissue on the contralateral side provides characterization of the lesion, in addition to analysis of intermetabolite ratios within the lesion.

[FIGURE 2 OMITTED]

In Lhermitte-Duelos disease, lesions can be diagnosed by their typical superficial striations on MR imaging; however, there are only a few reports of MRS findings for these lesions. (11) The characteristically enlarged folia is a result of a thickened internal granular layer secondary to replacement by hypertrophic ganglion cells, increased myelination of the adjacent molecular layer, and diminishment or complete absence of purkinje cells and astroglial/ganglion cells at the interface of the granular and molecular layers. (4,11) Hence, the superficial striations with T1 hypointensity and T2 hyperintensity correspond to the thinned white matter with filling cerebral spinal fluid (CSF), widened granular cell layer, and inner portions of the dysplastic molecular layer. (3)

In our patient, the LDD lesion, NAA, Cho, MI, and the Cr/Cho ratio were all found to be normal. Presence of lactate was definitively confirmed, which manifested as a doublet at approximately 1.3 parts per million (ppm). The lactate doublet had been consistently shown to undergo inversion from short to long TEs. The maintenance of NAA specific for brain tissue represented normal neuronal and axonal viability and essentially ruled out a neoplasm, as well as the remaining normal markers, including the creatinine/choline ration, suggested near-normal tissue. Lactate, however, is not normally present in the brain parenchyma. (10,12) The increased lactate most likely represented increased glycolysis in the lesion. These findings supported the proliferation of normal brain tissue as one would find in a dysplastic gangliocytoma of the cerebellum, Lhermitte Duclos disease.

In our patient, the initial MR of the brain, performed with and without contrast, identified an incidental cerebellar lesion. MR spectroscopy was an additional valuable tool to increase the diagnostic sensitivity and specificity of the MR to differentiate a benign from a malignant process that made a biopsy or surgical procedure unnecessary. In our case, MRS provided a unique assessment and metabolic signature in this unusual benign dysplastic cerebellar gangliocytoma, LDD. (11,12) In light of the findings of a benign cerebellar lesion, no intervention was warranted and the patient continued to be asymptomatic six months later.

REFERENCES

(1.) Klisch J, Juengling F, Spreer j, Koch D, Thiel T, Buchert M, Arnold S, Eeuerhke F, Schumacher M. Lhermitte-Duclos disease: assessment with MR imaging, position emission tomography, single-photon emission CT, and MR spectioscopy. AJNR Am j Neuroradiol 2001; 22:824-30.

(2.) Nowak DA, Trost HA. Lhermitte-Duclos disease (dysplastic cerebellar gangliocytoma): a malformation, hamartoma or neoplasm? Acta Neurol Scand 2002; 105:137-145

(3.) Barkovich A, Millen, Dobyns W. A developmental and genetic classification for midbrain-hindbrain malformations. Brain. 2009; 132(12): 3199.3323.

(4.) Zhou XP, Marsh D, Morrison C, Chaudhury A, Maxwell M, Reifenberger G, Eng C. Germline Inactivation of PTEN and Dysregulation of the Phosphoinositol-3-Kinase/Akt Pathway Cause Human Lhermitte-Duclos Disease in Adults. Am J Hum Genet. 2003; 73(5): 1191-1198

(5.) Gammon A, Jasperson K, Kohlmann W, Burt RW. Hamartomatous polyposis syndromes. Best Pract Res Clin Gastroenterol. 2009; 23(2):219-31

(6.) Majos C, Julia-Sape M, Alonso J, Serrallonga M, Aguilera C, Acebes JJ, Arus C, Gili j. Brain humor classification by proton MR spectroscopy: comparison of diagnostic accuracy at short and long TE. AJNR Am J Neuroradiol. 2004; 25(10): 1696-704.

(7.) Moller-Hartimann W, Herminghaus S, Krings T, Marquardt G, Lanfermann H, Pilatus U, Zanella FE. Clinical application of proton magnetic resonance spectroscopy in the diagnosis of infracranial mass lesions. Neuroradiology. 2002; 44(5): 371-81.

(8.) Thomas B, Krishnamoorthy T, Radhakrishnan VV, Kesavadas C: Advanced MR Imaging in Lhermitte-Duclos disease: moving closer to pathology and pathophysiology. (Diagnostic Neuroradiology) Neuroradiology (2007) 49:733-738.

(9.) Singh AK, Wang A-M, Sanders W. Magnetic resonance spectioscopy of the brain. Applied Radiology. 2002; 31(12): 58-65.

(10.) Wirt M, Petermann G. Magnetic resonance spectroscopy: A basic guide to data acquisition and interpretation. Applied Radiology. 2003; 32(4): 25-30.

(11.) Nagaraja S, Powell T, Griffiths PD, Wilkinson ID. MR imaging and spectioscopy in Lhermitte-Duclos disease. Neuroradiology. 2004; 46(5): 355-8.

(12.) Wu CH, Chai JW, Lee CH, Chen WH, Lee T, Chen CC. Assessment with magnetic resonance imaging and spectroscopy in Lhermitte-Duclos disease. J Chin Med Assoc. 2006

Christian Fauria-Robinson, MD; Rebecca Meyers, MD; Sarah Castillo-Jorge, MD; Jeremy Nguyen, MD; and Enrique Palacios, MD, FACR

Drs. Fauria-Robinson, Castillo-Jorge, Nguyen and Palacios are from the Department of Radiology at the Tulane University School of Medicine in New Orleans. Dr. Meyers is a resident in the department of Pediatrics at UCLA in Los Angeles, California.
COPYRIGHT 2014 Louisiana State Medical Society
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2014 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Fauria-Robinson, Christian; Meyers, Rebecca; Castillo-Jorge, Sarah; Nguyen, Jeremy; Palacios, Enriqu
Publication:The Journal of the Louisiana State Medical Society
Article Type:Clinical report
Date:Sep 1, 2014
Words:1517
Previous Article:Recognition and management of rodent-borne infectious disease outbreaks after heavy rainfall and flooding.
Next Article:Spontaneous rectus sheath hematoma: two variant cases.
Topics:

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters