CC BY-NC-ND 4.0 · Arquivos Brasileiros de Neurocirurgia: Brazilian Neurosurgery 2018; 37(04): 339-342
DOI: 10.1055/s-0038-1676530
Case Report | Relato de Caso
Thieme Revinter Publicações Ltda Rio de Janeiro, Brazil

Microsurgical Resection of Craniocervical Dermoid Cyst by Far Lateral Approach: Case Report and Literature Review

Ressecção microcirúrgica de cisto dermoide pela abordagem extremo-lateral: relato de caso e revisão da literatura
Lucas Crociati Meguins
1  Departament of Neurologic Sciences, Hospital de Base, São José do Rio Preto, São Paulo, Brazil
,
Antonio Ronaldo Spotti
1  Departament of Neurologic Sciences, Hospital de Base, São José do Rio Preto, São Paulo, Brazil
,
Dionei Freitas de Morais
1  Departament of Neurologic Sciences, Hospital de Base, São José do Rio Preto, São Paulo, Brazil
,
Carlos Eduardo Dall'Aglio Rocha
1  Departament of Neurologic Sciences, Hospital de Base, São José do Rio Preto, São Paulo, Brazil
,
Ricardo Lourenço Caramanti
1  Departament of Neurologic Sciences, Hospital de Base, São José do Rio Preto, São Paulo, Brazil
,
Mario José Góes
1  Departament of Neurologic Sciences, Hospital de Base, São José do Rio Preto, São Paulo, Brazil
› Author Affiliations
Further Information

Address for correspondence

Lucas Crociati Meguins, MD
Departamento de Ciências Neurológicas, Hospital de Base
Av. Brigadeiro Faria Lima, 5544, São José do Rio Preto, SP 15090-000
Brazil   

Publication History

10 July 2018

30 October 2018

Publication Date:
12 December 2018 (online)

 

Abstract

Introduction Intracranial dermoid tumors represent a rare clinical entity that accounts for 0.04 to 0.6% of all intracranial tumors. Their location in the posterior fossa is uncommon.

Objectives To report the case of a young woman with a posterior fossa dermoid cyst treated by right far lateral approach.

Case Report A 17-year-old woman presenting with swallowing difficulties for 6 weeks was referred for a neurological investigation. A magnetic resonance imaging (MRI) scan showed a hyperintense T1-weighted large expansive lesion occupying the posterior fossa and compressing the anterior face of the brain stem and cerebellum. The patient underwent surgical treatment by right far lateral approach with decompression of vascular and neural structures. The patient presented an uneventful recovery, and was discharged home on the fourth postoperative day without any additional neurological deficits. The anatomopathological analysis confirmed the diagnosis of dermoid cyst.

Conclusion The far lateral approach is a safe and feasible route to appropriately treat large posterior fossa dermoid cysts. Decompression of vascular and neural structures is essential to achieve good symptom control.


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Resumo

Introdução Tumores dermoides intracraniais são casos clínicos raros que representam de 0,04 a 0,6% de todos os tumores intracraniais. Sua localização na fossa posterior é incomum.

Objetivos Relatar o caso de uma jovem com cisto dermoide na fossa posterior tratado pela lateral direita.

Relato de Caso Paciente de 17 anos apresentando dificuldades de engolir há seis meses encaminhada para investigação neurológica. Imagem de ressonância magnética mostrou uma lesão larga hipertensa T1 ocupando a fossa posterior e comprimindo a face anterior do tronco cerebral e cerebelo. A paciente foi submetida a tratamento cirúrgico pela abordagem extremo-lateral direita com descompressão das estruturas vascular e neural. A paciente apresentou rápida melhora e recebeu alta 4 dias após o procedimento sem nenhum déficit neurológico. A análise anatomopatológica confirmou o diagnóstico de cisto dermoide.

Conclusão A abordagem extremo-lateral direita é o acesso mais seguro e factível para tratar apropriadamente largos cistos dermoides na fossa posterior. Descompressão das estruturas vascular e neural é fundamental para alcançar bom controle sintomático.


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Introduction

Dermoid cysts, also called dermoid tumors, are extremely rare benign congenital cystic masses of embryological origin that account for 0.04 to 0.6% of all intracranial tumors.[1] [2] [3] [4] Dermoid and epidermoid cysts arise from defects in the separation of the neuroectoderm during the formation of the neural tube, leading to sequestration of ectodermal remnants, and intracranial dermoid cysts occur at either end of the neuraxis and mostly near the midline.[5] [6] [7] Intracranial dermoids are found in the posterior fossa, supra, and parasellar regions.[8] [9] [10] Dermoids enlarge slowly and accumulate viscous or semi-solid yellow material composed of desquamated epithelium, sebaceous gland secretions, fat, oil, and hair. The presence of skin components (hair follicles, sebaceous, and sweat glands) in the cyst wall and contents distinguishes dermoids from epidermoid cysts.[11]

The aim of the present study is to describe the case of a young woman with a posterior fossa dermoid cyst treated by right far lateral approach.


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Case Report

A 17-year-old woman presenting with swallowing difficulties and headaches that had begun six weeks before was referred for a neurological investigation. The neurological examination revealed no motor deficits or cranial nerve palsy. A magnetic resonance imaging (MRI) scan showed a hyperintense T1-weighted large expansive lesion occupying the posterior fossa and compressing the anterior face of the brain stem and cerebellum ([Fig. 1]). The patient underwent surgical treatment by right far lateral approach on lateral position with cyst resection and decompression of vascular and neural structures ([Figs. 2] and [3]). The patient presented an uneventful recovery, and was discharged home on the fourth postoperative day without any additional neurological deficits. The anatomopathological analysis confirmed the diagnosis of dermoid cyst.

Zoom Image
Fig. 1 Magnetic resonance imaging scan showing an expansive lesion occupying the posterior fossa (right: preoperative images; left: postoperative images).
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Fig. 2 Patient positioning on left decubitus and drawing of skin incision performed in the right far lateral approach.
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Fig. 3 Intraoperative final view after total resection of the cystic lesion.

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Discussion

Dermoid cysts, also called dermoid tumors, are extremely rare benign congenital cystic masses of embryological origin that account for 0.04 to 0.6% of all intracranial tumors.[1] [2] [3] [4] Moreover, intracranial dermoid cysts have the component of keratinized squamous epithelium originated from the ectoderm, and composed of dermal materials like hair and sebaceous glands.[5] [6] [7] They are ∼ 3 to 10 times less frequent than epidermoid tumors, and have a tendency of being located near the subarachnoid space, sulci or fissures because of the space that presents minimal resistance to an easy growth rate, and the midline in the base of the skull.[12] [13]

Dermoid tumors located in the posterior fossa are frequent and usually require an appropriate surgical route to minimize brain retraction, postoperative edema and risk of recurrence.[14] [15] The far lateral approach seems to be an excellent route to totally remove posterior fossa lesions that occupy the most anterior face of brain stem, cerebellum and ventral foramen magnum.[16] [17] This approach has been used for many neurosurgical pathologies of the posterior fossa, including tumors, such as meningioma and chordoma, and posterior circulation aneurysm.[18] [19] [20] [21] Large cystic lesions involving the craniocervical junctions are also described as possible indications for a far lateral approach, once a better operative view of the cysts in the ventral dural space of the lower clivus and foramen magnum, and less risk of trauma to the brain stem and cervical cord, can be easily achieved with this approach.[22]

There are many descriptions of the far lateral approach technique. Classically, the standard incision for the far lateral suboccipital approaches has been the “reverse hockey stick” incision, in which the skin and muscles of the suboccipital area are elevated and reflected inferiorly.[14] [15] [16] [17] However, Lau and colleagues[21] proposed a C-shape incision as an alternative to reduce muscle retraction and postoperative cervical pain. Vertebral artery exposure is also an essential step to safely perform the approach. Campero and colleagues[23] highlighted the nuchal lines as anatomical landmarks to appropriately dissect the suboccipital muscles and expose the vertebral artery before performing the craniotomy. In the present report, we performed the far lateral approach to safely remove the lesion and preserve the neural and vascular structures compressed by the cyst.

In conclusion, the far lateral approach provides adequate exposure for the surgical treatment of ventral lesions in the craniocervical junction. Minimal retraction, preservation of involved neural structures and a refined microsurgical technique are the most important steps to safely remove dermoid cysts of the posterior fossa.


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Conflicts of Interest

The authors have none to declare.


Address for correspondence

Lucas Crociati Meguins, MD
Departamento de Ciências Neurológicas, Hospital de Base
Av. Brigadeiro Faria Lima, 5544, São José do Rio Preto, SP 15090-000
Brazil   


  
Zoom Image
Fig. 1 Magnetic resonance imaging scan showing an expansive lesion occupying the posterior fossa (right: preoperative images; left: postoperative images).
Zoom Image
Fig. 2 Patient positioning on left decubitus and drawing of skin incision performed in the right far lateral approach.
Zoom Image
Fig. 3 Intraoperative final view after total resection of the cystic lesion.