Monostotic fibrous dysplasia of the clivus. Case report

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

Fibrous dysplasia of the clivus - A case study and literature review

Fibrous dysplasia is a benign, congenital skeletal disorder which leads to the formation of fibro-osseous intramedullary bone lesions. Clival fibrous dysplasia is a rare variant which commonly presents asymptomatically with no findings on examination and is often picked up incidentally on radiological investigation. A 39-year-old female presented with a sudden onset headache of 3 days’ duration alongside diplopia and right lower limb weakness upon examination. Computerized tomography head scan revealed an expansile clivus with a ground-glass appearance, magnetic resonance imaging brain scan revealed a predominantly hypointense signal on T1- and T2-weighted images and subsequent whole-body bone imaging confirmed the diagnosis of monostotic clival fibrous dysplasia. This case highlights the importance of considering monostotic clival fibrous dysplasia as a differential diagnosis in patients presenting with sudden onset symptoms of headache alongside cranial and peripheral nerve involvement, when other more sinister causes have been excluded.

MR Imaging of Monostotic Fibrous Dysplasia of the Clivus

We describe the MR appearance of a case of monostotic fibrous dysplasia confined to the clivus. The lesion showed intermediate signal intensity on T2-weighted images which is uncommon among clival diseases.

Clival fibrous dysplasia: Case series and review of the literature

Slightly more than 30 cases of fibrous dysplasia involving the clivus have been reported in the international literature, primarily in the neurosurgery and radiology literature. In this article we present a series of 4 cases involving patients with clival fibrous dysplasia. In a retrospective chart review, 4 patients presenting to tertiary care centers from January 1, 2006, to January 31, 2008, were identified and their presenting symptoms and radiologic findings reviewed. Based on our literature review, we describe the presenting symptoms of patients with clival fibrous dysplasia and characterize the findings of imaging studies associated with this disorder. All patients in this series had a presenting complaint of headache or cranial nerve deficits, which is consistent with previous reports found in our literature review. Additional presenting symptoms that have been reported include dysphagia and a nontender occipital mass; there was also an incidental asymptomatic finding. Magnetic resonance imaging findings are consistent with those associated with fibrous dysplasia at other sites of the body. We conclude that clival involvement in monostotic fibrous dysplasia may not be as rare as previously perceived.

Surgical approaches to central skull base and postsurgical imaging

The close proximity to or intricate involvement of critical neurovascular structures in the central skull base region or both present unique surgical challenges. Varied surgical approaches may be used to remove tumors in this region, including open craniotomies and minimally invasive transnasal or transfacial endoscopic approaches. The ideal surgical technique is chosen based on multiple factors including the aggressiveness, histopathology, and location of the tumor with respect to regional neurovascular elements. Postsurgical image analysis of the central skull base requires an intimate understanding of preoperative and expected postoperative appearance in relation to the nature of the excision and surgical materials used.

Fibrous dysplasia of the clivus

Fibrous dysplasia (FD) of craniofacial structures is well documented, however, its involvement of the clivus is seldom described. We report a case of clival FD in a young man who presented with headache localized to the occipital area. The radiological studies revealed a monostotic disease confined to the clivus, with typical findings of hypointensity on magnetic resonance images and ground-glass density on computed tomography. The diagnosis of FD was confirmed on pathological examination of specimens taken through transsphenoidal surgery. The patient showed reduction of symptoms and no change of residual lesion on follow-up imaging taken 2.5 years later after surgery. This study includes clinical aspect, radiographic appearance, differential diagnosis and treatment strategy of this rare skull base lesion.

Características tomográficas da displasia fibrosa craniofacial: estudo retrospectivo de 14 casos

OBJETIVO: Apresentar as várias formas de displasia fibrosa craniofacial em um estudo revisional com 14 exames de tomografia computadorizada. MATERIAIS E MÉTODOS: Foram selecionados 14 casos de displasia fibrosa craniofacial atendidos no Serviço de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia e no Serviço de Diagnóstico por Imagem do Hospital Heliópolis, São Paulo, SP, entre 1991 e 2002. Foram avaliados, pelos autores, três dos achados tomográficos mais relevantes: o número de ossos acometidos, a apresentação radiológica predominante e a uni/bilateralidade da doença no crânio. RESULTADOS: Observou-se predomínio do padrão misto em relação à forma de apresentação da doença. Foram vistos, ainda, acometimento contíguo de dois ou mais ossos e equivalência entre casos de acometimento craniofacial unilateral e bilateral, possivelmente por conta dos pacientes serem, em sua maioria, portadores de displasia fibrosa do tipo monostótica. CONCLUSÃO: O conhecimento das características tomográficas da displasia fibrosa craniofacial é de grande importância para que seja feito planejamento cirúrgico adequado e seguimento pós-tratamento.

Displasia fibrosa do clivus: relato de caso

Relatamos o caso de uma paciente de 43 anos com história de cefaléia crônica e diplopia. O exame neurorradiológico demonstrou aumento de volume e alteração na densidade óssea do clivus. Foi submetida a cirurgia e o exame anatomopatológico evidenciou displasia fibrosa. Foram relatados na literatura outros 14 casos de displasia fibrosa envolvendo o clivus. Discutimos essa rara apresentação da doença segundo o quadro clínico, exames de imagem, histologia e tratamento.

Minimally invasive biopsy of parasellar lesions: safety and clinical applications of the endoscopic, transnasal approach

The base of the skull can be affected by a variety of tumours requiring a wide range of treatment modalities. In formulating a management plan, histological diagnosis can play an essential role. Existing methods of skull base biopsy, especially in the anatomically critical parasellar region, include either prolonged open skull base approaches or image-guided needle biopsies. The latter methods can be time-consuming and cannot reliably avoid surrounding critical neurovascular structures. The experience with an endoscopic, transnasal biopsy of parasellar tumours in selected patients is presented. A preliminary series of 11 patients harbouring parasellar lesions with some degree of extension to the sphenoid or maxillary sinus underwent endoscopic, transnasal biopsy. The procedure was diagnostic in all cases. There was no operative mortality and minimal morbidity only recorded. The biopsy results affected the patients' management and, based on these results, major skull base surgery was avoided in four cases. Direct endoscopic visualization prompted avoidance of a vascular catastrophe of an atypical vascular lesion. The endoscopic, transnasal biopsy appears to offer a number of advantages over existing methods in selected patients. It is minimally invasive as it employs the use of natural osseous corridors. Tissue sampling under direct visualization minimizes the risks of negative biopsies or damage to critical neurovascular structures. The use of additional imaging employed by image-guided needle biopsies in not necessary. When planning treatment of parasellar tumours, the endoscopic, transnasal route should be considered.

Fibrous dysplasia of the clivus with a second T8 bone lesion: case report

BACKGROUND

We present a rare case of a probably poliostotic fibrous dysplasia of the clivus in a young woman with a clival and vertebral involvement. We also compare our case with data reported in tables that include all cases of clival fibrous dysplasia present in literature.

CASE DESCRIPTION

Thirty-year-old women presented with headache. We reviewed radiological and clinical literature before surgery. It was possible to perform a preoperative diagnosis of fibrous dysplasia of the clivus so it was possible to adopt a minimally invasive surgical approach on the clivus. The diagnosis of fibrous dysplasia of the clivus was confirmed after the operation. As the patient was asymptomatic, we did not operate on the vertebral lesion which was stable after 1 year.

CONCLUSION

We draw the conclusion that it is possible to obtain a correct preoperative diagnosis of fibrous dysplasia based on magnetic resonance imaging and computed tomographic scans; this makes it possible to avoid major surgical operations. The reported case is particularly interesting because apart from the clival fibrous dysplasia, a vertebral involvement of the same type can be assumed; this association has never been reported in literature.

Fibrous dysplasia of the clivus

OBJECTIVE

Fibrous dysplasia is a developmental skeletal disorder that may lead to distortion, expansion, and weakening of the bone. Craniofacial involvement by this entity is well recognized and is known to cause neurovascular impingement and cosmetic deformity; fibrous dysplasia of the clivus, however, is unrecognized and seldom reported. Differentiating this entity from more aggressive disease processes affecting the clivus is central for the proper management of lesions in this area. We have studied fibrous dysplasia of the clivus with the goal of depicting its manifestations, outlining its management, and heightening awareness of this disease entity.

METHODS

We retrospectively reviewed our database and identified patients with the diagnosis of fibrous dysplasia of the clivus. The demographic data, the clinical and radiological findings, and the management of these patients were reviewed.

RESULTS

Eight patients who had experienced fibrous dysplasia of the clivus were identified. They either were asymptomatic (four patients) or presented with headache (four patients). Of the patients who presented with headache, one also had XIIth cranial nerve paralysis and another had dysphagia. The radiological findings for this entity were consistent, with typical findings of hypointensity on T1- and T2-weighted magnetic resonance imaging studies and ground-glass appearance on computed tomographic scans. Four of the patients in our series had pathological confirmation. Treatment was determined by the patient's symptoms.

CONCLUSION

Fibrous dysplasia should be considered in the differential diagnosis of lesions affecting the clivus. Its clinical and radiological presentations permit the establishment of the diagnosis. Its management is usually conservative, unless the patient presents with nerve compression or extensive symptomatic involvement of the condyle.