Skull Base Chordomas and Chondrosarcomas.

Skull base chordomas account for less than 0.2% and chondrosarcomas for less than 0.15% of all intracranial tumors. Although their clinical and imaging presentations are similar, they derive from different origins. Chordomas arise from embryonic remnants of the primitive notochord and chondrosarcomas from primitive mesenchymal cells or from the embryonic rest of the cranial cartilaginous matrix. Both entities are characterized by infiltration and destruction of the surrounding bone and soft tissue and a high locoregional recurrence rate. Chondrosarcomas, when treated with similar complex strategies, display a much better prognosis than chordomas. The overall survival is approximately 65% for chordomas and 80% for chondrosarcomas at 5 years and 30 and 50%, respectively, at 10 years. Chordomas are divided into the following 3 histological types: classical (conventional), chondroid, and dedifferentiated. Chondrosarcomas have conventional, mesenchymal, clear cell, and dedifferentiated subgroups. Both tumor entities often present with nonspecific symptoms, and headaches are the most reported initial symptom. Computed tomography and magnetic resonance imaging are required to determine the tumor localization and the extent of tumor growth. The treatment philosophy is to maximize tumor resection, minimize morbidity, and preserve function. Neurosurgical approaches commonly used for the resection of intracranial chordomas and chondrosarcomas are transsphenoidal, transbasal, cranio-orbitozygomatic, transzygomatic extended middle fossa, transcondylar, and transmaxillary approaches. Chordomas and chondrosarcomas are not sensitive to chemotherapy and there are no approved drugs for their treatment. The present treatment concept is a combination of surgical resection with a maximal excision and preserving patients' quality of life by adjuvant radiotherapy for both chordomas and chondrosarcomas.

Quality of life considerations for patients with anterior and central skull base malignancies.

INTRODUCTION: The extirpation of skull base malignancies may be associated with significant morbidity and can profoundly impact health related quality of life (HRQOL). In this review, we sought to provide an overview of HRQOL and the factors that influence it for patients with skull base malignancies. MATERIALS AND METHODS: Narrative review. RESULTS: HRQOL tends to improve in the months to years following treatment and is profoundly impacted by both tumor location and treatment approach. Wherever possible, HRQOL should always be elicited from the patient directly. Several HRQOL instruments have been used in this population including generic, site-specific and disease specific measures. CONCLUSION: Given that HRQOL is a multidimensional concept with several important facets, validated disease-specific instruments are generally preferred.

Clinical classification of clival chordomas for transnasal approaches.

Endoscopic endonasal approaches (EEAs) are ideal for most chordomas, but there is little information regarding the practical clinical classification of clival chordomas to guide surgery with EEAs. This article investigates a relatively concise and practical clinical classification system for clival chordomas and summarizes the clinical characteristics and operative key points of different clinical types. Here, 55 patients with clival chordomas treated through EEAs from 2012 to 2017 were retrospectively reviewed. Depending on the origin of the notochord and the growth pattern of the tumor, with our introduced Wang's line, these cases of clival chordoma were divided into types I-IV. There were 14 cases of type I-A, 7 cases of type I-B, 10 cases of type II, 10 cases of type III-A, 7 cases of type III-B, and 7 cases of type IV. The gross total resection (GTR) rate of primary and recurrent type I tumors was 64% and 25%, and residual tumors were found mainly in cases with involvement of the cavernous sinus or the posterior upper part of the dorsum sella. The GTR rate of primary and recurrent type II tumors was 85% and 66.6%, respectively. Residual tumors were found in cases with involvement of the petrous apex. The GTR rate of primary and recurrent type III tumors was 75% and 20%, and residual tumors were found in cases with involvement of the parapharyngeal space and dorsal side of C1-2. Residual type I-B and type III-B tumors were found when there was BA or VA adhesion or brain stem invasion. Our new classification method proposed here can be used to guide the resection of clival chordomas through EEAs.

Characterization of Skull Base Lesions Using Pseudo-Continuous Arterial Spin Labeling.

PURPOSE: Pseudo-continuous arterial spin labeling (pCASL) is a non-invasive magnetic resonance (MR) perfusion technique. Our study aimed at estimating the diagnostic performance of the pCASL sequence in assessing the perfusion of skull base lesions both qualitatively and quantitatively and at providing cut-off values for differentiation of specific skull base lesions. METHODS: In this study 99 patients with histopathologically confirmed skull base lesions were retrospectively enrolled. Based on a pathological analysis, the lesions were classified as hypervascular and non-hypervascular. Patients were divided into two subgroups according to the anatomical origin of each lesion. The MRI study included pCASL and 3D T1-weighted fat-saturated post-contrast sequences. Of the patients seven were excluded due to technical difficulties or patient movement. The lesions were classified by two raters, blinded to the diagnosis as either hyperperfused or non-hyperperfused, based on the pCASL sequence. The normalized tumor blood flow (nTBF) of each lesion was determined. Qualitative and quantitative characteristics of hypervascular and non-hypervascular lesions were compared. RESULTS: Visual assessment enabled correct classification of 98% of the lesions to be performed. Quantitatively, we found significant differences between the nTBF values for hypervascular and non-hypervascular lesions (p < 0.001) and provided cut-off values, allowing meningioma and schwannoma to be distinguished from meningioma and adenoma. Significant differences were also found within the hypervascular group, namely, paraganglioma was more hyperperfused than meningioma (p = 0.003) or metastases (p = 0.009). CONCLUSION: The present study demonstrates the high diagnostic performance of pCASL in characterizing skull base lesions by either visual assessment or nTBF quantification. Adding the pCASL sequence to the conventional protocol of skull base assessment can be recommended.

Evaluation of Patients with Sinonasal and Ventral Skull Base Malignancies.

A wide variety of tumors present in the sinonasal and ventral skull base. Patients often have nonspecific symptoms initially and present with advanced tumors, affecting the orbit and other adjacent structures. Evaluation of these malignancies with modern imaging techniques can define tumor invasion, but biopsy is often required to establish a diagnosis because most have a nonspecific appearance. A thorough understanding of the anatomy is the key to treatment planning, and a multidisciplinary approach determines the optimal strategy.

Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumors of the Nasal Cavity, Paranasal Sinuses and Skull Base.

The sinonasal tract remains an epicenter of a diverse array of neoplasia. This paper discusses changes to the WHO classification system of tumors involving this area. In particular, seromucinous hamartoma, NUT carcinoma, biphenotypic sinonasal sarcoma, HPV-related carcinoma with adenoid cystic features, SMARCB1-deficient carcinoma, and renal cell-like adenocarcinoma are discussed.

Clinical efficacy and safety of surface imaging guided radiosurgery (SIG-RS) in the treatment of benign skull base tumors.

Frameless, surface imaging guided radiosurgery (SIG-RS) is a novel platform for stereotactic radiosurgery (SRS) wherein patient positioning is monitored in real-time through infra-red camera tracking of facial topography. Here we describe our initial clinical experience with SIG-RS for the treatment of benign neoplasms of the skull base. We identified 48 patients with benign skull base tumors consecutively treated with SIG-RS at a single institution between 2009 and 2011. Patients were diagnosed with meningioma (n = 22), vestibular schwannoma (n = 20), or nonfunctional pituitary adenoma (n = 6). Local control and treatment-related toxicity were retrospectively assessed. Median follow-up was 65 months (range 61-72 months). Prescription doses were 12-13 Gy in a single fraction (n = 18), 8 Gy × 3 fractions (n = 6), and 5 Gy × 5 fractions (n = 24). Actuarial tumor control rate at 5 years was 98%. No grade ≥3 treatment-related toxicity was observed. Grade ≤2 toxicity was associated with symptomatic lesions (p = 0.049) and single fraction treatment (p = 0.005). SIG-RS for benign skull base tumors produces clinical outcomes comparable to conventional frame-based SRS techniques while enhancing patient comfort.

[Transnasal endoscopic surgery of communicating neoplasm outside cerebral dura mater and orbital fasciae].

Objective:This paper is intend to observe the feasibility of surgical approach with which communicating neoplasm outside cerebral dura mater and orbital fasciae was removed by transnasal endoscopic surgery.Method:Nine patients suffered from communicating neoplasm in the area of naso-orbital-cranio complex were treated with transnasal endoscopic surgery. The size of skull base bone defect was from 1.25 cm×1.13 cm to 3.25 cm×2.69 cm. No eye enucleation was done. No reconstructions of skull base and medial wall of orbital cavity were done. Iodoform gauze was packed in paranasal sinuses fourteen days. Patients with malignant tumor were treated radiation therapy and chemical therapy after surgical treatment. The degree of resection, complications of intracranial and orbital cavities, survival condition were the focus of this study.Result:The tumor were completely removed and all operations were successfully completed by trasnasal endoscopic surgery. Only one patient was required blood transfusion due to seriously bleeding from tumor during the operation. There was no orbital, intracranial, and vascular complications. The defect of bone at skull base and lamina papyracea were automatic reconstructed. Three patients have showed recurrence of neoplasm, and two of them died during two years of following up time.Conclusion:Transnasal endoscopic surgery is a safe, reliable and effective approach to treat communicating neoplasm in the area of naso-orbital-cranio complex, of which main part of tumor exists in the sinunasal cavity.

A simple classification of cranial-nasal-orbital communicating tumors that facilitate choice of surgical approaches: analysis of a series of 32 cases.

Cranial-nasal-orbital communicating tumors involving the anterior and middle skull base are among the most challenging to treat surgically, with high rates of incomplete resection and surgical complications. Currently, there is no recognized classification of tumors with regard to the choice of surgical approaches. From January 2004 to January 2014, we classified 32 cranial-nasal-orbital communicating tumors treated in our center into three types according to the tumor body location, scope of extension and direction of invasion: lateral (type I), central (type II) and extensive (type III). This classification considerably facilitated the choice of surgical routes and significantly influenced the surgical time and amount of hemorrhage during operation. In addition, we emphasized the use of transnasal endoscopy for large and extensive tumors, individualized treatment strategies drafted by a group of multidisciplinary collaborators, and careful reconstruction of the skull base defects. Our treatment strategies achieved good surgical outcomes, with a high ratio of total resection (87.5 %, 28/32, including 16 cases of benign tumors and 12 cases of malignant tumors) and a low percentage of surgical complications (18.8 %, 6/32). Original symptoms were alleviated in 29 patients. The average KPS score improved from 81.25 % preoperatively to 91.25 % at 3 months after surgery. No serious perioperative complications occurred. During the follow-up of 3 years on average, four patients with malignant tumors died, including three who had subtotal resections. The 3-year survival rate of patients with malignant tumors was 78.6 %, and the overall 3-year survival rate was 87.5 %. Our data indicate that the simple classification method has practical significance in guiding the choice of surgical approaches for cranial-nasal-orbital communicating tumors and may be extended to other types of skull base tumors.

Classification and surgical approaches for transnasal endoscopic skull base chordoma resection: a 6-year experience with 161 cases.

The aim of this study is to retrospectively analyze 161 cases of surgically treated skull base chordoma, so as to summarize the clinical classification of this tumor and the surgical approaches for its treatment via transnasal endoscopic surgery. Between August 2007 and October 2013, a total of 161 patients (92 males and 69 females) undergoing surgical treatment of skull base chordoma were evaluated with regard to the clinical classification, surgical approach, and surgical efficacy. The tumor was located in the midline region of the skull base in 134 cases, and in the midline and paramedian regions in 27 cases (extensive type). Resection was performed via the transnasal endoscopic approach in 124 cases (77%), via the open cranial base approach in 11 cases (6.8%), and via staged resection combined with the transnasal endoscopic approach and open cranial base approach in 26 cases (16.2%). Total resection was achieved in 38 cases (23.6%); subtotal resection, 86 cases (53.4%); partial resection of 80-95%, 29 cases (18%); and partial resection <80%, 8 cases (5%). The clinical classification method used in this study seems suitable for selection of transnasal endoscopic surgical approach which may improve the resection degree and surgical efficacy of skull base chordoma. Gross total resection of skull base chordoma via endoscopic endonasal surgery (with addition of an open approach as needed) is a safe and viable alternative to the traditional open approach.

[Epidemiology, diagnosis, clinical symptoms, and classification of malignant primary skull base tumors]. / Épidemiologiia, diagnostika, klinicheskaia simptomatika i klassifikatsiia pervichnykh zlokachestvennykh opukholei, porazhaiushchikh osnovanie cherepa.

A review of literature presents up-to-date information on the prevalence, incidence, clinical manifestations, diagnosis, and classification of malignant primary skull base tumors (MPSBTs). In the structure of total cancer incidence, malignant head and neck tumors account for 5% of all annual cancer deaths in the USA and are among the 5 most common groups of tumors in males worldwide. These tumors develop most often in the sixth decade of life, occurring 2 times more often in males than in females. In Russia, the MPSBT incidence (as of 2012) was 0.62% out of all newly diagnosed malignant tumors. The incidence rate amounts to 0.66 per 100 000 population and is significantly higher than the global rate (0.44 per 100 000). About half of all malignant skull base tumors have the epithelial nature and affect the anterior parts of the skull base. The most frequent histological types of malignant skull base tumors are squamous cell carcinoma, adenocarcinoma, and non-Hodgkin's B cell lymphoma. Treatment of skull base tumors is an interdisciplinary problem and the area of interest of otolaryngologists, dentists, ophthalmologists, neurosurgeons, plastic surgeons, radiologists, and chemotherapists. Physical and endoscopic examinations, endoscopic transnasal biopsy, CT, MRI, PET/CT, and ultrasound are typically used for verification of the diagnosis, tumor staging, and selection of the treatment approach. The review describes the criteria for TNM staging of malignant tumors of the nasal cavity and paranasal sinuses in accordance with the 7th version of the TNM recommendations of the American Joint Committee on Cancer (AJCC). The TNM-based staging depends on the location (maxillary sinus, nasal cavity, or ethmoid labyrinth) and histological structure of the tumor, which, in turn, determines the tactics of comprehensive treatment and a prognosis group.

Exploitation of Simple Classification and Space Created by the Tumor for the Treatment of Foramen Magnum Meningiomas.

OBJECTIVE: The resection of foramen magnum meningiomas (FMMs) presents neurosurgical challenges. We propose a simple classification of the tumor location and the operating space created by the tumor to help treatment planning. METHODS: We retrospectively analyzed 16 FMMs and divided them into 3 groups based on the tumor location--clival, foraminal, and atlantal tumors. The distance between the condyle and the neuraxis at the level of the foramen magnum was measured and defined as the available operative space (AOS). We also reviewed intraoperative video recordings to assess the surgical exposure of the tumor by the space created by the FMM and compared it with the AOS. RESULTS: There were 4 clival, 8 foraminal, and 4 atlantal tumors. The AOS of the clival tumors was 10 mm ± 1.7, the AOS of the foraminal tumors was 18 mm ± 3.7, and the AOS of the atlantal tumors was 12 mm ± 2.1. All foraminal and atlantal tumors could be detached without a brain retractor. Because a major portion of the clival tumors was covered by the spinomedullary junction, a brain spatula was needed to obtain the required surgical space. The difference in AOS between clival and foraminal/atlantal tumors was statistically significant (P = 0.044). Although 4 patients experienced postoperative complications, the average postoperative Karnofsky performance scale score improved. The surgical complication rate was significantly lower in foraminal and atlantal FMMs than in clival FMMs (P = 0.027). CONCLUSIONS: The simple classification of the tumor location helped to assess surgical difficulties. Knowledge of the space created by the FMMs between the condyle and the neuraxis is useful for planning the approach strategy, especially for estimating the available working space without resection of the occipital condyle.

Planum Sphenoidale and Tuberculum Sellae Meningiomas: Operative Nuances of a Modern Surgical Technique with Outcome and Proposal of a New Classification System.

BACKGROUND: The resection of planum sphenoidale and tuberculum sellae meningiomas is challenging. A universally accepted classification system predicting surgical risk and outcome is still lacking. OBJECTIVES: We report a modern surgical technique specific for planum sphenoidale and tuberculum sellae meningiomas with associated outcome. A new classification system that can guide the surgical approach and may predict surgical risk is proposed. METHODS: We conducted a retrospective review of the patients who between 2005 and March 2015 underwent a craniotomy or endoscopic surgery for the resection of meningiomas involving the suprasellar region. Operative nuances of a modified frontotemporal craniotomy and orbital osteotomy technique for meningioma removal and reconstruction are described. RESULTS: Twenty-seven patients were found to have tumors arising mainly from the planum sphenoidale or the tuberculum sellae; 25 underwent frontotemporal craniotomy and tumor removal with orbital osteotomy and bilateral optic canal decompression, and 2 patients underwent endonasal transphenoidal resection. The most common presenting symptom was visual disturbance (77%). Vision improved in 90% of those who presented with visual decline, and there was no permanent visual deterioration. Cerebrospinal fluid leak occurred in one of the 25 cranial cases (4%) and in 1 of 2 transphenoidal cases (50%), and in both cases it resolved with treatment. There was no surgical mortality. CONCLUSION: An orbitotomy and early decompression of the involved optic canal are important for achieving gross total resection, maximizing visual improvement, and avoiding recurrence. The visual outcomes were excellent. A new classification system that can allow the comparison of different series and approaches and indicate cases that are more suitable for an endoscopic transsphenoidal approach is presented.

Selection of surgical approaches based on semi-quantifying the skull-base invasion by petroclival meningiomas: a review of 66 cases.

BACKGROUND: Petroclival meningiomas are still challenging for neurosurgeons. In the present study, we reviewed 66 petroclival meningiomas that underwent craniotomy to assess the surgical approaches for petroclival meningiomas based on semi-quantifying tumor extension to skull base and to evaluate the outcomes. METHODS: According to invasion characteristics, skull base related to petroclival meningiomas was semi-quantitatively divided into five regions: upper, middle, and lower petroclival regions (region A, B, and C, respectively), cerebellopontine angle region (region D), and parasellar and cavernous sinus region (region E). Appropriate surgical approaches were adopted for petroclival meningiomas with varying degrees of invasion, including the subtemporal (11/66), retrosigmoid (15/66), presigmoid (32/66), combined retrosigmoid and far-lateral (2/66), supra-infratentorial (4/66), and extended middle cranial fossa (2/66) approaches. RESULTS: The results showed that involvement of region A, B, and C was in 64, 50, and eight patients, respectively. Invasion to region D and E occurred in 13 and 39 cases, respectively. The ratio of single region involvement was only 7.6 %, whereas most petroclival meningiomas tended to invade more regions (39.4 % for two, 37.9 % for three, 12.1 % for four, and 3.0 % for five regions, respectively). Gross total resection was achieved in 29 cases (43.9 %), near total resection in 27 cases (40.9 %), and subtotal resection in ten cases (15.2 %). After a mean follow-up period of 32.21 months, obvious cranial nerve deficits existed in seven patients, and recurrence occurred in eight patients. CONCLUSIONS: We introduced a simple and practicable method for classification of petroclival meningiomas, which could semi-quantify tumor invasion and help to select surgical approaches. With careful preoperative evaluation, a cautiously selected approach would improve the prognosis.

Craniofacial reconstruction following oncologic resection.

The ability to reliably reconstruct complex and sizable wounds has decreased the morbidity of skull base surgery substantially, preventing major complications and allowing treatment of tumors previously considered inoperable. Addressing facial nerve function with static and dynamic procedures as well as fabrication of craniofacial prostheses to replace delicate facial landmarks has further increased surgeons' ability to restore the appearance and function of the face.

Surgical management of tympanojugular paragangliomas with intradural extension, with a proposed revision of the Fisch classification.

BACKGROUND: Tympanojugular paragangliomas (TJPs) with intradural extension can be successfully treated by a single or staged procedure with low surgical morbidity. OBJECTIVES: To present the clinical findings and treatment methods used for surgically treating TJP with intradural extension, as well as to discuss the complications of treatment and the relative merits of single versus staged surgery by using a comprehensive literature review comparing objective outcome measures. STUDY DESIGN: A retrospective case review of 45 cases of TJP with intradural extension. SETTING: A quaternary skull base and neurotologic center. MATERIALS AND METHODS: The charts of 45 patients with Fisch classification class C or D TJP with intradural extension, who were operated on from April 1988 to April 2010, were analyzed. Clinical findings and preoperative lower cranial nerve (LCN) palsy as well as postoperative totality of resection, postoperative LCN palsy and complications were studied. The types, indications, and distribution of staged procedures were also analyzed. RESULTS: Out of 45 cases, 22 were C3di2. The IX and X cranial nerves were the commonest nerves affected preoperatively. Preoperative internal carotid artery management was performed in 16 cases. Twenty-nine cases had a single procedure and 16 had a staged procedure. The main indication for staged procedures was intradural extension of 2 cm or more. The infratemporal fossa approach (ITFA) type A was the main procedure in all cases. Overall, total resection was achieved in 68.8% of cases with postoperative cerebrospinal fluid leak in 4.4% cases. Postoperative House-Beckmann grade I-III facial nerve status was maintained in 80% of cases, and overall LCN preservation rate was 56.9%. There were no cases requiring tracheostomy, and 3 cases required delayed phonosurgical procedures to improve their voice. CONCLUSIONS: TJP with intradural extension can be successfully managed with the judicious use of staged procedures to reduce the incidence of postoperative cerebrospinal fluid leak. The ITFA did not cause an excessively high rate of facial nerve palsy, and the overall total resection and LCN preservation rate compares very favorably with previously published data.

Triple dumbbell-shaped jugular foramen schwannomas.

PURPOSE: Triple dumbbell-shaped jugular foremen schwannomas (DSJFSs) have high cervical extension according to Bulsara's classification. One-stage, single-discipline, total removal of triple DSJFSs is not always possible due to their both intracranial and cervical extensions. We evaluated our experience in one-stage resection of triple DSJFSs by using a combined neurosurgical and head and neck approach. METHODS: Between October 2004 and May 2009, eight patients with triple DSJFSs were treated surgically at our institute. The clinical and radiological features, operative procedures and outcomes are retrospectively reviewed. RESULTS: Total tumour removal was achieved in seven patients and near total in one. New cranial nerve (CN) paresis occurred after surgery in one patient and worsening of preoperative CN deficits was noted in three. Two patients experienced cerebrospinal fluid leakage and one of them had a repeated operation with closure of the dural deficit. Follow-up period ranged from 23 to 60 months (mean 38 months). All CN dysfunction had improved considerably at the last follow-up examination. There have been no clinical or radiological signs of tumour recurrence. CONCLUSIONS: One-stage total resection of triple DSJFSs can be achieved by a multidisciplinary cranial base team composed of neurosurgeons and head and neck surgeons via a craniocervical approach.

Vertebral artery involvement by tympanojugular paragangliomas: management and outcomes with a proposed addition to the fisch classification.

OBJECTIVES: To present the management and outcomes of cases of tympanojugular paraganglioma (TJP) with vertebral artery (VA) involvement, and to propose the addition of the new 'V' category to the Fisch classification. MATERIALS AND METHODS: Retrospective analysis of data from a quaternary neuro-otologic and skull base referral center. We studied 230 TJP patients to identify the cases with VA involvement and present their management, surgical findings and outcome. RESULTS: Out of 230 patients, 8 patients were found to have VA involvement by TJP. The extradural artery was involved in 1 patient and the intradural VA was involved in 6 patients. The intradural and extradural VA were simultaneously involved in 1 patient. Seven of the 8 patients underwent surgery. In 2 patients, preoperative occlusion was performed (1 with balloon, 1 with coils). In 5 of these 7 patients, the tumor was successfully separated from the VA by microdissection with or without endovascular intervention. In another patient, the tumor together with the involved VA was removed. Of 7 patients who had surgery, 1 patient did not undergo endovascular intervention and had subtotal tumor removal from the VA. There were no serious complications in removing the tumor from around the VA. CONCLUSION: Although uncommon, the intradural or extradural VA can be involved by TJP. To avoid vascular accidents, the VA should be thoroughly evaluated at the planning stage. We advocate that the addition of a 'V' category would help to identify patients who need individualized VA management as part of a complete surgical evaluation.