Background Endoscopic skull‐base surgery (ESBS) is employed in the management of diverse skull‐base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull‐base surgery have produced the International Consensus Statement on Endoscopic Skull‐Base Surgery (ICAR:ESBS). Methods Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence‐based review or evidence‐based review with recommendations format. Subsequently, each topic was written and then reviewed by skull‐base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus. Results The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull‐base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated. Conclusion A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence‐based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull‐base community to embrace these opportunities and collaboratively address these shortcomings.

Skull base endoscopic reconstructive techniques have significantly advanced in the past decade. The use of pedicled mucosal flaps in the reconstruction of large dural defects resulting from an endoscopic transnasal craniotomy permits a robust repair. The CSF leak rate in this study is comparable to that achieved in open approaches. The ability to manage the skull base defects successfully with this approach greatly increases the utility of transnasal endoscopic surgery.

No abstract

Transclival meningoceles and primary spontaneous cerebrospinal fluid (CSF) leaks at the clivus are extremely rare lesions and only few of them have been reported in the literature. We report here six cases of transclival primary spontaneous CSF leaks through the clivus. A retrospective case study was performed. We reviewed six cases involving sinonasal CSF leaks located at the clivus treated between 1997 and 2009. Presenting symptoms, duration of symptoms, defect size, site of defect, surgical approach and technique of defect closure, intraoperative complications, postoperative complications, and recurrences are discussed. All CSF leaks were located in the upper central part of the clivus. two of six patients showed signs of increased intracranial pressure (ICP) including arachnoid pits and/or empty sella. For three patients a purely transnasal approach was used with multilayer reconstruction using a nonvascularized graft, and three patients underwent a transnasal transseptal approach with a multilayer reconstruction, with nasoseptal flap. No recurrences of CSF leaks at clivus or other sites were observed to date with a mean follow-up of 10.3 years (range, 3–15 years). Spontaneous CSF rhinorrhea located at the clivus is an extremely rare condition. To date, only eight cases have been described. Here, we report the largest group of six consecutive cases. Irrespective of the used reconstruction technique in all cases a 100% closure rate was achieved. However, identification of increased ICP is an essential aspect and this condition should be treated either medically or surgically.

No abstract

-Benign osteoblastoma is an uncommon bone tumor accounting for approximately 1% of all bone tumors. There are only 35 cases of skull osteoblastoma reported in the literature. We describe the case of a 23 year old male with a giant osteoblastoma of temporal bone submitted to a total removal of the tumor after an effective embolization of all external carotid branches. The authors discuss diagnostic and management aspects of this uncommon skull tumor.KEY WORDS: osteoblastoma, temporal bone, embolization. Osteoblastoma gigante de osso temporal: relato de casoRESUMO -Osteoblastoma é tumor benigno raro representando cerca de 1% de todos os tumores ósseos. Até o momento apenas 35 casos com acometimento craniano foram descritos na literatura. Os autores descrevem um caso de osteoblastoma gigante de osso temporal em paciente de 23 anos do sexo masculino. O tumor foi completamente ressecado após embolização de ramos nutrientes oriundos da carótida externa. São discutidos aspectos diagnósticos e terapêuticos deste raro tumor craniano. PALAVRAS-CHAVE: osteoblastoma, osso temporal, embolização.Benign osteoblastoma is an uncommon bone tumor accouting for approximately 1% of all bone tumors 1 . This neoplasm was initially reported by Jaffe and Mayer in 1932 under various names such as "osteogenic fibroma of bone" and "giant osteoma osteoid" 2 . The current term was proposed in 1956 by Jaffe 3 and Lichtenstein 4 . Since then, there was an increasing number of cases reported in the literature, most of them arising in the axial skeleton ( spine and major long bones of the lower extremities ).Skull lesions have been sporadically described and count for 2.3 to 20% of all cases 4,5 , most of them in the temporal bone. Their incidence is still controversial but there is no more than 35 cases of skull osteoblastoma reported in the literature. We present a case of a giant temporal osteoblastoma and discuss the best pre and intraoperative management of these patients. CASE REPORTA 23 year old male presented with a 3 years history of headache and swelling in his left temporal region associated with hearing impairment in the ipsilateral ear. The local examination disclosed a hard and painful mass in the left temporal bone with extension to the parietal region. Neurological examination was normal except

No abstract

Chordomas are rare tumors of the central nervous system and primarily occur in the extradural space. We report two patients with intracranial chordomas located in the region ofthe clivus that invaded the prepontine cisterns. The patients, 45 and 62 years old, had histories ofcranial neuropathies and headache, respectively. Petrosal approaches were performed in both with radical resection of the tumors. Anatomopathological studies confirmed the diagnosis ofchordoma. The symptoms of both patients resolved, and they have had no recurrence after 18 months of follow-up. Intradural chordomas or extradural chordomas that invade the intradural space are difficult to differentiate from ecchordoses physaliphorae, a non-neoplastic entity with similar radiological features. MBI-1 studies were therefore performed to confirm the diagnosis ofchordoma. The differential diagnosis for these two entities, the different modalities of treatment, and prognosis are reviewed.