Benign bony lesions of paranasal sinuses and skull base: from osteoma to fibrous dysplasia.

PURPOSE OF REVIEW: Benign bony lesions of the craniofacial complex are relatively common. However, their location close to critical neurovascular structures may render their treatment, if required, highly challenging.This article reviews the current literature on their pathophysiology, diagnosis, natural course and treatment, with a focus on most recent findings. RECENT FINDINGS: A new classification has been suggested concerning endoscopic resectability. The ratio of lateral frontal to interorbital distance can accurately and reliably predict the endoscopic reach to lateral frontal sinus, while orbital transposition can assist us in reaching lateral frontal sinus when anatomy is unfavorable. New and combined endoscopic transnasal and transorbital approaches are now in the surgical armamentarium. Prophylactic optic nerve decompression in fibrous dysplasia is absolutely contraindicated as it leads to worse visual outcomes. Radiotherapy of such lesions is of no benefit and may lead to a higher risk of malignant transformation. The presence of Guanine Nucleotide binding protein Alpha Stimulating (GNAS) mutation in chromosome 20 is universally present in fibrous dysplasia and can differentiate them from ossifying fibromas. SUMMARY: Diagnosis and therapeutic management of benign craniofacial bone lesions remains challenging. If surgical treatment is contemplated, the morbidity of the intervention should always be weighed against the potential benefits. Evolution of extended endoscopic endonasal and transorbital surgery means that more lesions can be reached purely endoscopically with better oncological and cosmetic results.

Primary Intracranial Adenoid Cystic Carcinoma: Report of Three Cases.

Objective Nasal cavity and paranasal sinuses host a variety of malignant tumors with adenoid cystic carcinoma (ACC) being the most frequent cancer of salivary gland origin. The histological origin of such tumors virtually precludes primarily intracranial localization. The aim of this study is to report cases of primarily intracranial ACC without evidence of other primary lesions at the end of an exhaustive diagnostic workup. Methods An electronic medical record search complemented by manual searching was conducted to identify prospective and retrospective cases of intracranial ACCs treated in Endoscopic Skull Base Centre Athens at the Hygeia Hospital, Athens from 2010 until 2021 with a mean follow-up time of at least 3 years. Patients were included if after complete diagnostic workup there was no evidence of a nasal or paranasal sinus primary lesion and extension of the ACC. All patients were treated with a combination of endoscopic surgeries performed by the senior author followed by radiotherapy (RT) and/or chemotherapy. Results Three unique illustrative cases (ACC involving the clivus, cavernous sinus and pterygopalatine fossa, one orbital ACC with pterygopalatine fossa and cavernous sinus involvement and one involving cavernous sinus, and Meckel's cave with extension to the foramen rotundum) were identified. All patients underwent subsequently proton or carbon-ion beam radiation therapy. Conclusions Primary intracranial ACCs constitute an extremely rare clinical entity with atypical presentation, challenging diagnostic workup and management. The design of an international web-based database with a detailed report of these tumors would be extremely helpful.

International Consensus Statement: Spontaneous Cerebrospinal Fluid Rhinorrhea.

BACKGROUND: The association between spontaneous cerebrospinal fluid (CSF) leak/rhinorrhea and idiopathic intracranial hypertension (IIH) has been increasingly recognized over the last years. However, considerable variability of opinion regarding the assessment, investigations, and management of patients with spontaneous CSF rhinorrhea remains. METHODS: A consensus group was formed from experts from Europe, Asia, Australia, South and North America. Following literature review and open discussions with members of the panel, a set of 61 statements was produced. A modified Delphi method was used to refine expert opinion with 3 rounds of questionnaires and a consensus group meeting in Santo-Rhino meeting in September 2019. RESULTS: Fifty statements (82% of total) on spontaneous CSF leak and IIH reached consensus. In 38 of 50 statements, the median response was 7 (strongly agree) and in the 12 remaining statements the median response was 6 (agree). Eleven statements were excluded because they did not reach consensus and one new statement was added during SantoRhino meeting. The final statements refer to patient history and clinical examination ("History taking should include presence of headache, tinnitus and visual defects"), investigations (role of Thin Slice Computed Tomography and CISS/FLAIR sequences in Magnetic Resonance Imaging), principles of management (watchful waiting or measures to reduce ICP are supplementary but cannot subsitute surgical closure), surgical technique, intraoperative, early postoperative and long term management. CONCLUSION: We present fifty consensus statements on the diagnosis, investigation, and management of spontaneous CSF rhinorrhea based on the currently available evidence and expert opinion. Although by no means comprehensive and final, we believe they can contribute to the standardization of clinical practice. Early diagnosis, prompt surgical closure of the defect, assesment for and treatment of potentially co-existing idiopathic intracranial hypertension in a comprehensive multidisciplinary approach are essential in order to successfully manage spontaneous CSF rhinorrhea, reduce associated morbidity and prevent recurrence.

Advances in vascularized flaps for skull base reconstruction.

PURPOSE OF REVIEW: Advances in anterior skull base surgery have resulted in the increasing diversification of reconstructive techniques. New vascularized flaps have been suggested in the last years, some quite similar, whereas new uses and applications have been suggested for some vascularized flaps, which have already established their value over the last decades. In this article, we describe the developments in skull base reconstruction with vascularized flaps and analyse the international experience in the use of vascularized flaps published with a focus on the last 18 months. RECENT FINDINGS: Over the past 18 months, a number of novel or modified vascularized intranasal flaps have been described, focusing on reconstruction of larger defects, the medial orbital wall, the anterior skull base (septal flip-flap) and dissection of the nasoseptal flap from the SPA foramen. Extranasal vascularized flaps, which have been around for a long time, still have their rightful place in skull base reconstruction and have recently been adjusted for endoscopic use. SUMMARY: We present an overview of the latest developments in vascularized flaps (intranasal and extranasal), their new implications, their modifications and complications or predictions of viability.

Extended endoscopic endonasal skull base surgery: from the sella to the anterior and posterior cranial fossa.

Skull base surgery has gone through significant changes with the development of extended endoscopic endonasal approaches over the last decade. Initially used for the transphenoidal removal of hypophyseal adenomas, the endoscopic transnasal approach gradually evolved into a way of accessing the whole ventral skull base. Improved visualization, avoidance of brain retraction, the ability to access directly tumours with minimal damage to critical neurosurgical structures as well lack of external scars are among its obvious benefits. However, it presents the surgeons with a number of challenges, including the need to deal endoscopically with potential arterial bleeding, complicated reconstruction requirements as well as the need for a true team approach. In this review drawing from our experience as well as published series, we present an overview of current indications, challenges and limitations of the expanded endonasal approaches to the skull base.