Posterior fossa gangliocytoma with facial nerve invasion: case report

Gangliocitoma de fossa posterior com invasão de nervo facial: relato de caso

Posterior fossa gangliocytoma with facial nerve invasion

Case report

Gangliocitoma de fossa posterior com invasão de nervo facial: relato de caso

Andrei Koerbel^I; Daniel Monte-Serrat Prevedello^II; Cláudio Esteves Tatsui^II; Luciano Pellegrino^III; Ricardo Alexandre Hanel^I; Luiz Fernando Bleggi-Torres^IV; João Cândido Araújo^V

Divisions of Neurosurgery and Pathology of Hospital Nossa Senhora das Graças, Curitiba PR, Brazil

^INeurosurgeon

Divisions of Neurosurgery and Pathology of Hospital Nossa Senhora das Graças, Curitiba PR, Brazil

^IIResident in Neurosurgery

Divisions of Neurosurgery and Pathology of Hospital Nossa Senhora das Graças, Curitiba PR, Brazil

^IIIMedical Student

Divisions of Neurosurgery and Pathology of Hospital Nossa Senhora das Graças, Curitiba PR, Brazil

^IVPathologist

Divisions of Neurosurgery and Pathology of Hospital Nossa Senhora das Graças, Curitiba PR, Brazil

^VNeurosurgeon Coordinator of the Residency Program in Neurosurgery

ABSTRACT

A 5 year-old boy with a cerebellar gangliocytoma with a peripheral right facial paresis and ataxia is presented. His MRI showed a heterogenous, diffuse lesion, isointense on T1 and hyperintense on T2-weigthed sequences, involving the right cerebellar hemisphere with direct extension into the right facial nerve. The present case is the first description of a gangliocytoma with direct facial nerve invasion, as demonstrated for the facial nerve paresis and supported by MRI and surgical inspection.

Key words: gangliocytoma, facial paresis, facial nerve, CNS tumor.

RESUMO

Um menino de 5 anos de idade com gangliocitoma cerebelar manifestando paralisia facial periférica e ataxia é apresentado. O estudo de ressonância magnética (RM) mostrou lesão difusa e heterogênea isointensa em T1 e hiperintensa em sequências ponderadas em T2, envolvendo o hemisfério cerebelar direito com extensão direta ao nervo facial direito. O presente caso é a primeira descrição de gangliocitoma com invasão direta do nervo facial, tal como demonstrado por paralisia facial periférica a direita e sustentado por RM e inspeção cirúrgica.

Palavras-chave: gangliocitoma, paralisia facial, nervo facial, tumor de SNC.

A case of conventional gangliocytoma involving the cerebellum, brainstem and superior cervical spinal cord with right facial nerve invasion is presented. Gangliocytomas are rare, benign, well differentiated, slowly growing neuroepithelial tumors composed of neoplastic, mature ganglion cells¹. Cranial nerve invasion by the lesion is extremely rare, with only one case of trigeminal nerve involvement previously reported in the literature². To our knowledge the present case is the first one showing facial nerve invasion.

CASE

A 5 year-old boy was referred to our institution for evaluation of peripheral right facial paresis and ataxia. He started with slowly progressive right facial weakness one year before admission. Three months later, his mother noticed gait disturbance and difficulty with his right arm. Two months before admission, he started with vomiting and headache. His neurological examination revealed peripheral right facial paresis, ataxia, and right sided dysmetria. A CT scan showed obstructive hydrocephalus caused by a diffuse right sided cerebellar lesion, hypodense in nature, with heterogenous contrast enhancement. He was submitted to a ventriculoperitoneal (VP) shunt, with relief of syntoms due to intracranial hypertension. A cranial MRI performed three days after VP shunt showed a heterogenous, diffuse lesion, isointense on T1-weigthed images, hyperintense on T2-weigthed sequences, at the right cerebellar hemisphere involving the superior part of cerebellar vermis, right middle cerebellar peduncle, pons and medulla oblongata (Fig 1). The lesion extented inferiorly to upper cervical spinal cord. A direct extension into the right vestibulo-cohclear-facial complex was also detected from brainstem through the internal acoustic meatus (Fig 2).

He was submitted to a right suboccipital craniectomy, with partial resection of lesion, limited to cerebellar tissue. Direct inspection of cranial nerve complex showed diffuse thickening of the facial nerve, from its central origin towards the periphery, entering the internal auditory canal. Histopathological examination was compatible with conventional gangliocytoma, showing diffuse proliferation of mature-looking nerve cells in a disorganized pattern. No necrosis and no mitosis were seen (Fig 3). One week after surgery, some improvement in the degree of ataxia and dysmetria was noted but facial paresis remained unchanged. At one-year follow-up, he showed a stable neurologic condition. MRI obtained at that time demonstrated no further progression of the lesion.

DISCUSSION

Neuronal and mixed neuronal-glial tumors are extremely rare, accounting for 0.1% to 0.5% of all brain tumors³. They are mostly seen in children and young people³, but the age of incidence ranges from 2 months to 80 years¹. They include gangliocytoma, dysplastic gangliocytoma of the cerebellum (Lhermite-Duclos Disease), ganglioglioma, dysembryoplastic neuroepithelial tumor, central neurocytoma, cerebellar liponeurocytoma and paraganglioma. Some authors consider ganglioneuroma as a synonym for gangliocytoma. Such terminology is not accepted by the World Health Organization classification of tumors and its use should be avoided. De Arriba-Vilamor et al. state that their pathogenesis is not fully understood, considering the possibility of being dysplasias or malformations rather than true neoplasias⁴.

The most frequent site for gangliocytomas is the temporal lobe, but they can arise anywhere in the central nervous system, such as in the cerebellum, brainstem, floor of third ventricle and spinal cord. ⁵ Image findings are not specific. At MRI, the tumor would emit a low-intensity signal on T1-weighted sequences and a high-intensity signal on T2. Contrast enhancement varies in intensity from none to marked, and it may be solid, heterogeneous, rim or nodular. Differential diagnosis on imaging includes astrocytomas and oligodendrogliomas as well other tumors of neuronal origin⁶. Gangliocytomas are usually radioresistant, therefore surgical removal is the only option with a favorable prognosis, even in those cases of partial resection.

There is only one description of cranial nerve invasion by gangliocytoma in the literature, where Abe et al report a case of trigeminal nerve involvement². To our knowledge the present case is the first description of direct facial nerve invasion by gangliocytoma, as demonstrated clinically and supported by MRI and surgical inspection.

Received 22 August 2002, received in final form 24 October 20002

Accepted 7 November 2002

Dr. Andrei Koerbel - Rua Alcides Munhoz 433 - 80810-040 Curitiba PR - Brasil. FAX: [phone]. E-mail: [e-mail]

• 1. Nelson JS, Bruner JM, Wiestler OD, VandenBerg SR. Ganglioglioma and gangliocytoma. In Kleihues P, Cavenee WK (eds). Pathology and genetics of tumors of the nervous system. Lyon: IARCPress, 2000:96-98.
• 2. Abe T, Asano T, Manabe T, Matsura H, Furuta T, Taguchi K. Trigeminal ganglioneuroma. Brain Tumor Pathol 1999;16:49-53.
• 3. Ebina K, Suzuki S, Takahashi T, Iwabuchi T, Takei Y. Gangliocytoma of the pineal body: a case report and review of the literature. Acta Neurochir (Wien) 1985;74:134-140.
• 4. Arriba-Vilamor C, Martinez-Mata A, Espinosa-Mogro H, Rubio-Viguera V. Ganglion cell tumors. Rev Neurol (Barc) 1998;27:1008-1011.
• 5. Atlas SW. Magnetic resonance imaging of the brain and spine. New York: Raven Press, 1991:266-273.
• 6. Peretti-Viton P, Perez-Castillo AM, Raybaud C, et al. Magnetic resonance imaging in gangliogliomas and gangliocytomas of the nervous system. J Neuroradiol 1991;8:189-1991.

Publication Dates

• Publication in this collection
  22 Sept 2008
• Date of issue
  June 2003

History

• Accepted
  07 Nov 2002
• Received
  22 Aug 2002
• Reviewed
  24 Oct 2002