Tumors of the skull base in children: review of tumor types and management strategies

Special Considerations in Pediatric Endoscopic Skull Base Surgery

Originally pioneered in adults, endoscopic endonasal approaches for skull base pathology are being increasingly applied as a minimally invasive alternative for young children. Intrinsic anatomic differences between these patient populations have sparked discussions on the feasibility, safety, and efficacy of these techniques in pediatric patients. This work aims to serve as a primer for clinicians engaged in the rapidly evolving field of pediatric endoscopic skull base surgery. A succinct overview of relevant embryology, sinonasal anatomy, and diagnostic workup is presented to emphasize key differences and unique technical considerations. Additional discussions regarding select skull base lesions, reconstructive paradigms, potential surgical complications, and postoperative care are also highlighted in the setting of multidisciplinary teams.

Pediatric Craniofacial Tumor Reconstruction

Effective management of pediatric craniofacial tumors requires coordinated input from medical, oncologic, and surgical specialties. Reconstructive algorithms must consider limitations in pediatric donor tissue and account for future growth and development. Immediate reconstruction is often focused on filling dead space, protecting underlying structures, and ensuring skeletal symmetry. Staged reconstruction occurs after the patient has reached skeletal maturity and is focused on restoring permanent dentition. Reconstructive options vary depending on the location, size, and composition of resected tissue. Virtual surgical planning (VSP) reduces the complexity of pediatric craniofacial reconstruction and ensures more predictable outcomes.

Imaging of pediatric calvarial and skull base tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

A standardized imaging protocol for pediatric oncology patients is essential for accurate and efficient imaging, while simultaneously promoting collaborative understanding of pathologies and radiologic assessment of treatment response. The objective of this article is to provide standardized pediatric imaging guidelines and parameters for evaluation of tumors of the pediatric orbit, calvarium, skull base, and temporal bone. This article was drafted based on current scientific literature as well as consensus opinions of imaging experts in collaboration with the Children's Oncology Group Diagnostic Imaging Committee, Society of Pediatric Radiology Oncology Committee, and American Society of Pediatric Neuroradiology.

Minimally invasive endoscopic approaches to pediatric skull base pathologies

OBJECTIVE

Endoscopic endonasal approaches to pediatric skull base lesions are rare, challenging, and present distinct considerations from adult pathology. In this study, we describe our endoscopic technical approach to various skull base lesions demonstrating the efficacy and nuances of these approaches in pediatric patients.

METHODS

Pediatric patients underwent endoscopic approach for skull base lesions from January of 2015 to April of 2021 were included in the study. Presenting symptoms, indications for surgery, surgical outcomes, intraoperative and postoperative complications, length of hospital stay, and length of follow-up were documented.

RESULTS

A total of 18 patients (median age 12, age-range 1-15, 53% male) underwent 19 endoscopic transsphenoidal procedures. The pathologies included craniopharyngioma (N = 5), biopsy for an unknown disease (n = 2; orbital meningioma and pituitary lymphocytic hypophysitis), pituitary adenoma (N = 2; ACTH-secreting and non-functional), Rathke's cleft cyst (n = 2), CSF leak repairs (n = 2; post-traumatic and spontaneous meningocele), juvenile nasopharyngeal angiofibroma (n = 3, 1 patient had 2 procedures) and rhabdomyosarcoma (n = 1). GTR was achieved in 11 out of 15 procedures (73.3%). Out of 10 patients with a sellar lesion, 6 patients had intraoperative CSF leak (60%). No patients experienced post-operative CSF leak. The median follow-up for all patients was 14 months (1-36 months).

CONCLUSION

Anterior and middle skull base pathology in pediatric patients can be effectively operated via an endoscopic approach across a wide variety of patient ages and conditions. Minimally invasive techniques with middle turbinate and nasal septum preservation can be achieved without compromising outcomes. A wide variety of surgical repair strategies can be successfully utilized.

Ten years of battle with multiple recurrences of pediatric skull base chondrosarcoma: A case report

In children and adolescents presenting with skull base sarcoma, treatment strategies will face challenging decisions due to the unique chemoresistant pathologies, limitations imposed by the not-yet fully mature anatomical structures, and the small surgical site.

HID: The Hybrid Image Decomposition Model for MRI and CT Fusion

Multimodal medical image fusion can combine salient information from different source images of the same part and reduce the redundancy of information. In this paper, an efficient hybrid image decomposition (HID) method is proposed. It combines the advantages of spatial domain and transform domain methods and breaks through the limitations of the algorithms based on single category features. The accurate separation of base layer and texture details is conducive to the better effect of the fusion rules. First, the source anatomical images are decomposed into a series of high frequencies and a low frequency via nonsubsampled shearlet transform (NSST). Second, the low frequency is further decomposed using the designed optimization model based on structural similarity and structure tensor to get an energy texture layer and a base layer. Then, the modified choosing maximum (MCM) is designed to fuse base layers. The sum of modified Laplacian (SML) is used to fuse high frequencies and energy texture layers. Finally, the fused low frequency can be obtained by adding fused energy texture layer and base layer. And the fused image is reconstructed by the inverse NSST. The superiority of the proposed method is verified by amounts of experiments on 50 pairs of magnetic resonance imaging (MRI) images and computed tomography (CT) images and others, and compared with 12 state-of-the-art medical image fusion methods. It is demonstrated that the proposed hybrid decomposition model has a better ability to extract texture information than conventional ones.

Pediatric Skull Base Tumors: A Management Challenge

Context

Skull base tumors are varied in children and are particularly challenging to pediatric neurosurgeons, with few papers in the literature describing the evolution, complications, and outcome. The authors evaluated long-term outcomes in children submitted to skull base tumor surgery and performed a literature review.

Aims

The aim of this study was to analyze surgical results, complications, and outcomes, on comparison with previous publications.

Materials and Methods

A retrospective analysis of children undergoing surgery at a single institution between 2000 and 2018 for lesions of the cranial base was carried out. In addition, a literature review was carried out describing a total of 115 children operated on for skull base tumors.

Statistical Analysis

Chi-squared and Fisher's exact tests were performed to compare the distribution of categorical variables and a nonparametric Mann-Whitney U test was used to perform intergroup comparisons of continuous variables.

Results

Seventeen children ranging in age from 8 months to 17 years (mean, 10.9 years) underwent skull base approaches. Tumor types included schwannoma, meningioma, chondroid chordoma, mature teratoma, epidermoid cyst, hemangiopericytoma, rhabdomyosarcoma, myofibroblastic inflammatory tumor, fibromyxoid sarcoma, Crooke's cell adenoma, ossifying fibroma, osteoblastoma, nasopharyngeal angiofibroma and Ewing's sarcoma. Gross total resection was achieved in 6 patients (35.3%), 12 patients (70.6%) had benign histology, and 5 patients (29.4%) had a malignant tumor. Transient postoperative cerebrospinal fluid leak affected only one patient. Thirteen children (76.4%) had a residual neurological deficit at last follow-up evaluation. Three (17.6%) surviving patients received adjuvant therapy. The rate of recurrence or lesion progression was 17.6%.

Conclusions

Skull base tumors in children present a therapeutic challenge because of their unique pathological composition and can lead to considerable morbidity and mortality in pediatric age.

Endoscopic Skull Base Surgery in the Pediatric Population

Background

Surgery is often indicated for definitive biopsy or as the primary treatment modality for pediatric skull base lesions. Traditionally, open surgical approaches were utilized to address pediatric skull base pathology. However recently, expanded endoscopic sinus surgery has been utilized as a minimally invasive approach to addressing skull base pathology in the pediatric population.

Purpose

This review provides an overview of the current literature evaluating the unique anatomic challenges of the pediatric skull and the safety and efficacy of expanded skull base procedures in the pediatric population.

Findings

The pediatric skull base and sinus anatomy is small and continues to develop throughout childhood leading to unique surgical challenges. Sphenoid sinus pneumatization and intercarotid distance at the skull base are two significant anatomic challenges to pediatric skull base surgery. Despite the distinctive anatomy challenges, recent studies demonstrate that the safety and efficacy of expanded endoscopic sinus surgery appear to be equivalent to traditional open surgical approaches.

Conclusion

Expanded endoscopic sinus surgery in the pediatric population has similar efficacy and safety as the traditional open approaches.

Craniopharyngiomas: Challenges and Controversies

Despite its benign histopathology, the treatment of craniopharyngioma remains one of the most formidable challenges faced by skull base surgeons. The technical challenges of tackling these complex central skull base lesions are paralleled by clinical challenges related to their unique tumor biology and the often-complex decision making required. In this article, we critically appraise the most recent literature to explore the challenges and controversies surrounding the management of these lesions. The role of curative resections and the shift in the surgical paradigm toward the multidisciplinary goal-directed management approach are discussed.

Robot-assisted stereotactic biopsy of pediatric brainstem and thalamic lesions

OBJECTIVE

Biopsies of tumors located in deep midline structures require highly accurate stereotaxy to safely obtain lesional tissue suitable for molecular and histological analysis. Versatile platforms are needed to meet a broad range of technical requirements and surgeon preferences. The authors present their institutional experience with the robotic stereotactic assistance (ROSA) system in a series of robot-assisted biopsies of pediatric brainstem and thalamic tumors.

METHODS

A retrospective analysis was performed of 22 consecutive patients who underwent 23 stereotactic biopsies of brainstem or thalamic lesions using the ROSA platform at Rady Children's Hospital in San Diego between December 2015 and January 2020.

RESULTS

The ROSA platform enabled rapid acquisition of lesional tissue across various combinations of approaches, registration techniques, and positioning. No permanent deficits, major adverse outcomes, or deaths were encountered. One patient experienced temporary cranial neuropathy, and 3 developed small asymptomatic hematomas. The diagnostic success rate of the ROSA system was 91.3%.

CONCLUSIONS

Robot-assisted stereotactic biopsy of these lesions may be safely performed using the ROSA platform. This experience comprises the largest clinical series to date dedicated to robot-assisted biopsies of brainstem and diencephalic tumors.

CT and MRI features of calvarium and skull base osteosarcoma (CSBO)

OBJECTIVE

This study aims to assess the CT and MRI features of calvarium and skull base osteosarcoma (CSBO).

METHODS

The CT and MRI features and pathological characteristics of 12 cases of pathologically confirmed CSBO were analyzed retrospectively.

RESULTS

12 patients (age range 9-67 years; 3 male, 9 female) were included in the study. Tumours occurred in skull base (7, 58.3%), temporal (4, 33.3%) and frontal (1, 8.3%). Among all, six patients received radiotherapy for nasopharyngeal carcinoma. According to pathology, 11 out of 12 tumours were high-grade (91.7%). On CT, all the tumours had soft tissue mass penetrated into cortical bone with invasion of surrounding soft tissue. Six tumours were shown to have lytic density and six were mixed density. Matrix mineralization was present in 10 cases (83.3%). On MRI, tumours presented as soft-tissue masses measuring 5.9 ± 2.4 (3.9-8.0) cm. Five tumours showed low signal intensities on T₁ weighted imaging with seven having heterogeneous signal intensities. One showed low signal intensity on T₂ weighted imaging, two showed high signal intensities and nine heterogeneous signal intensities. All the tumours showed low signal intensities on diffusion-weighted imaging. On contrast enhanced images, seven cases showed heterogeneous enhancement, three showed peripheral enhancementand and two showed homogeneous enhancement. Dural tail sign were detected in nine cases.

CONCLUSION

CSBO is rare, and is commonly associated with previous radiation exposure. A presumptive diagnosis for osteosarcoma should be considered when calvarium and skull base tumours with osteoid matrix and duraltail sign are found.

ADVANCES IN KNOWLEDGE

CT and MR features of CSBO have not been reported. The study helps to identify CSBO and other sarcomas.

Peel-Away Catheter Introducer Sheath for Reducing Nasal Traumatic Injury During Pediatric Endoscopic Skull Base Surgery

OBJECTIVE

Pediatric endoscopic endonasal surgery represents a still-growing discipline to approach complex skull base lesions and is characterized by unfavorable anatomical conditions. Children have very small nostrils and narrow rhinosinusal corridors, which could lead more easily to accidental injury to the nasal structures. We describe the use of a peel-away catheter introducer sheath as an innovative and minimally invasive technique to further reduce surgical trauma to the nasal mucosa and structures in pediatric rhinoneurosurgery.

METHODS

From January 2009 to December 2018, the peel-away sheath technique was used in 6 pediatric endoscopic procedures for biopsy and/or removal of skull base tumors.

RESULTS

The endoscopic technique with the use of the peel-away catheter allowed clear visualization of the surgical field during the whole course of the procedure and good surgical maneuverability. The use of the peel-away sheath did not prolong the surgical operation time and provided a good working channel. No intraoperative or postoperative major complications were observed. No nasal short-term complications were registered in all patients.

CONCLUSIONS

The use of a peel-away catheter introducer sheath technique represents a valid adjunct in the endoscopic pediatric skull base surgery repertoire. It can help in avoiding inadvertent surgical traumas to the sinonasal structures, especially by residents and junior surgeons. This could potentially reduce postoperative nasal morbidity.

125 I interstitial brachytherapy in management of pediatric skull base tumors

BACKGROUND

The purpose of this study was to present our preliminary assessment of the safety and efficacy of ¹²⁵ I interstitial brachytherapy (IBT) in the management of pediatric skull base tumors.

METHODS

Thirty pediatric patients with skull base tumors treated with ¹²⁵ I IBT from April 2007 to May 2017 were included in this study. The probabilities of local control (LC) and overall survival (OS) were calculated by the Kaplan-Meier method.

RESULTS

The one- and two-year LC rates were 96.7% and 74.8%, respectively. The one- and two-year OS rates were 93.3% and 72.2%, respectively. No severe acute toxicity was observed. Severe late toxicities were observed in one (3.33%) of 30 patients.

CONCLUSION

¹²⁵ I IBT is effective and safe in the management of pediatric skull base tumors, with satisfactory cosmetic and functional outcomes.

[Variability and age-related features of the anatomy of the midline structures of the anterior skull base]

The article presents the literature data on the structural variability and age-related features of the midline anatomical structures of the anterior skull base (frontal sinus, ethmoid bone, anterior parasellar region, and medial orbital wall). This is the area of surgical interests of neurosurgeons and rhinosurgeons. The study objective is to analyze the literature data on the individual variability and age-related anatomy of these structures. The work is illustrated with original images from the authors' personal archive. The individual anatomical features of eloquent structures in the surgical area (structures within the surgical corridor, key anatomical landmarks, optic tract, internal carotid and ethmoidal arteries, etc.) should be considered in planning surgery in patients of all age groups because they can limit the view and the amount of safe manipulations or increase the risk of complications. The presented data may be useful for neurosurgeons and otolaryngologists whose surgical interests are focused on the midline structures of the anterior skull base.

Lateral Skull Base Approaches in Pediatric Skull Base Surgery

Lateral skull base pathology is rare in children. Awareness of the potential for lateral skull base lesions in children is imperative for timely identification and appropriate management. Some of the common presentations and pathologies shall be presented, as well as a variety of approaches that may be utilized to access the lateral skull base in the pediatric patient. Although the lateral skull base approaches utilized in adults may also be considered for management of pediatric lesions, some special considerations given the small developing anatomy need to be kept in mind.

Developmental Considerations in Pediatric Skull Base Surgery

Objectives  To review developmental surgical anatomy and technical nuances related to pediatric skull base surgery. Design  Retrospective, single-center case series with literature review. Setting  MD Anderson Cancer Center. Participants  Patients undergoing pediatric skull base surgery. Main Outcome Measures  Review developmental anatomy of the pediatric skull base as it relates to technical nuance of various surgical approaches and insight gained from a 25-year institutional experience with this unique patient population. Results  Thirty-nine patients meeting these criteria were identified over a 13-year period from 2003 to 2016 and compared to a previously reported earlier cohort from 1992 to 2002. The most common benign pathologies included nerve sheath tumors (11%), juvenile nasopharyngeal angiofibromas (9.5%), and craniopharyngiomas (4.8%). The most common malignancies were chondrosarcoma (11%), chordoma (11%), and rabdomyosarcoma (11%). Varied surgical approaches were utilized and were similar between the two cohorts save for the increased use of endoscopic surgical techniques in the most recent cohort. The most common sites of tumor origin were the infratemporal fossa, sinonasal cavities, clivus, temporal bone, and parasellar region. Gross total resection and postoperative complication rates were similar between the two patient cohorts. Conclusions  Pediatric skull base tumors, while rare, often are treated surgically, necessitating an in depth understanding of the anatomy of the developing skull base.

Robot-assisted procedures in pediatric neurosurgery

OBJECTIVE

During the last 3 decades, robotic technology has rapidly spread across several surgical fields due to the continuous evolution of its versatility, stability, dexterity, and haptic properties. Neurosurgery pioneered the development of robotics, with the aim of improving the quality of several procedures requiring a high degree of accuracy and safety. Moreover, robot-guided approaches are of special interest in pediatric patients, who often have altered anatomy and challenging relationships between the diseased and eloquent structures. Nevertheless, the use of robots has been rarely reported in children. In this work, the authors describe their experience using the ROSA device (Robotized Stereotactic Assistant) in the neurosurgical management of a pediatric population.

METHODS

Between 2011 and 2016, 116 children underwent ROSA-assisted procedures for a variety of diseases (epilepsy, brain tumors, intra- or extraventricular and tumor cysts, obstructive hydrocephalus, and movement and behavioral disorders). Each patient received accurate preoperative planning of optimal trajectories, intraoperative frameless registration, surgical treatment using specific instruments held by the robotic arm, and postoperative CT or MR imaging.

RESULTS

The authors performed 128 consecutive surgeries, including implantation of 386 electrodes for stereo-electroencephalography (36 procedures), neuroendoscopy (42 procedures), stereotactic biopsy (26 procedures), pallidotomy (12 procedures), shunt placement (6 procedures), deep brain stimulation procedures (3 procedures), and stereotactic cyst aspiration (3 procedures). For each procedure, the authors analyzed and discussed accuracy, timing, and complications.

CONCLUSIONS

To the best their knowledge, the authors present the largest reported series of pediatric neurosurgical cases assisted by robotic support. The ROSA system provided improved safety and feasibility of minimally invasive approaches, thus optimizing the surgical result, while minimizing postoperative morbidity.

Minimally invasive surgery of the anterior skull base: transorbital approaches

Minimally invasive approaches are becoming increasingly popular to access the anterior skull base. With interdisciplinary cooperation, in particular endonasal endoscopic approaches have seen an impressive expansion of indications over the past decades. The more recently described transorbital approaches represent minimally invasive alternatives with a differing spectrum of access corridors. The purpose of the present paper is to discuss transorbital approaches to the anterior skull base in the light of the current literature. The transorbital approaches allow excellent exposure of areas that are difficult to reach like the anterior and posterior wall of the frontal sinus; working angles may be more favorable and the paranasal sinus system can be preserved while exposing the skull base. Because of their minimal morbidity and the cosmetically excellent results, the transorbital approaches represent an important addition to established endonasal endoscopic and open approaches to the anterior skull base. Their execution requires an interdisciplinary team approach.

Pathologic aspects of skull base tumors

Skull base tumors form a highly heterogeneous group. As there are several structures in this anatomical site, a large number of different primary malignancies might develop, as well as a variety of secondary (metastatic) tumors. In this article, the most common malignancies are presented, along with a short histopathologic description. For some entities, an immunohistochemical profile is also given that should be helpful in proper diagnosis. As many pathologic diagnoses nowadays also include genetic studies, the most common genetic abnormalities in skull base tumors are presented.

Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons

BACKGROUND

Chordomas are rare tumours affecting the skull base. There is currently no clear consensus on the post-surgical radiation treatments that should be used after maximal tumour resection. However, high-dose proton beam therapy is an accepted option for post-operative radiotherapy to maximise local control, and in the UK, National Health Service approval for funding abroad is granted for specific patient criteria.

OBJECTIVES

To review the indications and efficacy of proton beam therapy in the management of skull base chordomas. The primary outcome measure for review was the efficacy of proton beam therapy in the prevention of local occurrence.

METHODS

A systematic review of English and non-English articles using MEDLINE (1946-present) and EMBASE (1974-present) databases was performed. Additional studies were reviewed when referenced in other studies and not available on these databases. Search terms included chordoma or chordomas. The PRISMA guidelines were followed for reporting our findings as a systematic review.

RESULTS

A total of 76 articles met the inclusion and exclusion criteria for this review. Limitations included the lack of documentation of the extent of primary surgery, tumour size, and lack of standardised outcome measures. Level IIb/III evidence suggests proton beam therapy given post operatively for skull base chordomas results in better survival with less damage to surrounding tissue.

CONCLUSIONS

Proton beam therapy is a grade B/C recommended treatment modality for post-operative radiation therapy to skull base chordomas. In comparison to other treatment modalities long-term local control and survival is probably improved with proton beam therapy. Further, studies are required to directly compare proton beam therapy to other treatment modalities in selected patients.

A retrospective study of skull base neoplasia in 42 dogs

This study describes the prevalence and distribution of 42 cases of skull base neoplasia in dogs between 2000 and 2014. The average age of affected individuals was 9.5 years, and there was no sex or breed predisposition. The most common skull base neoplasms were meningioma (25 cases) and pituitary adenoma (9 cases). Less common tumors included craniopharyngioma (2 cases), nerve sheath tumor (2 cases), and 1 case each of pituitary carcinoma, meningeal oligodendrogliomatosis, presumed nasal or sinonasal carcinoma, and multilobular tumor of bone. All neoplasms caused some degree of compression of adjacent structures. The distribution of the tumors was greatest in the sellar region ( n = 18), followed by the paranasal region ( n = 12), caudal cranial fossa ( n = 10), central cranial fossa ( n = 1), and rostral cranial fossa ( n = 1).

Endoscopic endonasal surgery for sinonasal and skull base lesions in the pediatric population

Endoscopic endonasal skull base surgical techniques, initially developed in adult patients, are being utilized with increasing frequency in pediatric patients to treat sinonasal and skull base lesions. This article reviews the current state of endoscopic endonasal approaches to the skull base to both treat disease and reconstruct the skull base in pediatric patients. Sinonasal and skull base embryology and anatomy are reviewed as a foundation for understanding the disease processes and surgical techniques. Selected skull base pathologies and conditions that involve the pediatric skull base are also reviewed.

Intracranial chordoma presenting as acute hemorrhage in a child: Case report and literature review

Background:

Chordomas are rare, slow-growing malignant neoplasms derived from remnants of the embryological notochord. Pediatric cases comprise only 5% of all chordomas, but more than half of the reported pediatric chordomas are intracranial. For patients of all ages, intracranial chordomas typically present with symptoms such as headaches and progressive neurological deficits occurring over several weeks to many years as they compress or invade local structures. There are only reports of these tumors presenting acutely with intracranial hemorrhage in adult patients.

Case Description:

A 10-year-old boy presented with acute onset of headache, emesis, and diplopia. Head computed tomography and magnetic resonance imaging of brain were suspicious for a hemorrhagic mass located in the left petroclival region, compressing the ventral pons. The mass was surgically resected and demonstrated acute intratumoral hemorrhage. Pathologic examination was consistent with chordoma.

Conclusion:

There are few previous reports of petroclival chordomas causing acute intracranial hemorrhage. To the authors’ knowledge, this is the first case of a petroclival chordoma presenting as acute intracranial hemorrhage in a pediatric patient. Although uncommon, it is important to consider chordoma when evaluating a patient of any age presenting with a hemorrhagic lesion of the clivus.

Corridor-based endonasal endoscopic surgery for pediatric skull base pathology with detailed radioanatomic measurements

BACKGROUND

Pediatric anatomy is more restricted, and the propagation of endonasal endoscopic approaches in the pediatric population has been limited.

OBJECTIVE

To demonstrate the feasibility of the endonasal endoscopic approach in a variety of age groups and to perform measurements of the corridors and spaces available for surgery as a guide for case selection.

METHODS

Only patients <18 years were included. The choice of operative corridor/approach is described in relation to pathological entity and location. Preoperative/postoperative visual fields and endocrine panels, extent of resection, as well as postoperative long-term complications are described. Prospective magnetic resonance image-based anatomic measurements of key distances were performed to determine age-dependent surgical indications and limitations.

RESULTS

Forty purely endoscopic procedures were performed in 33 pediatric patients (5-18 years of age) harboring a variety of skull base lesions, from benign tumors to congenital malformations. For the 20 patients in whom gross total resection was the intended goal of surgery, gross total resection was attained in 15 (75%). There were 2 infections (5%) and no cerebrospinal fluid leaks. Significant improvement was shown in 58.3% of patients with visual deficits. Hormone overproduction resolved in 75% of patients, while preoperative hormone insufficiency only improved in 29.2%. Wider intercarotid distance at the superior clivus (P = .01) and shorter nare-dens working distance (P = .001) predicted improved outcomes and fewer postoperative complications.

CONCLUSION

Endonasal endoscopic skull base approaches are viable in the pediatric population, they are not impeded by sphenoid sinus aeration, and they have minimal risk of cerebrospinal fluid leak and meningitis. Outcomes and complications can be predicted based on specific radio anatomical skull base measurements rather than age.

Malignant fibrous histiocytoma of the scalp: A rare differential with a dramatic clinical presentation

Malignant fibrous histiocytoma (MFH) a pleomorphic sarcoma of uncertain origin was first described by O'Brien and Stout in 1964. It is the most common primary soft tissue sarcoma of late adult life; its occurrence is rare in the pediatric population. MFHs are commonly known to arise in the extremities and the trunk although it can occur almost anywhere in the body. MFH of the scalp is extremely rare; moreover, there is paucity of literature with regards to prevalence of scalp and skull neoplasms. We present an unusual case of a primary MFH involving the scalp of a 5-year-old child and discuss its unusual clinical presentation, histology with immunohistochemistry correlation and its management. Reviewing the literature of primary MFH of the scalp, our patient to the best of our knowledge, is probably the youngest case reported so far.

Meningiomas of the pediatric skull base: a review

Pediatric skull base meningiomas are rare and complex clinical entities. Meningioma is a relatively uncommon brain tumor in children, and only ∼ 27% involve the skull base. Some evidence suggests that these tumors are more likely to be atypical or malignant in children than adults. The absence of female preponderance in pediatric meningiomas is reflected in the skull base subpopulation. Skull base meningiomas in children are most likely to be found in the anterior or middle fossa base, or involving the orbit and optic nerve sheath. Petroclival, suprasellar/parasellar, cerebellopontine angle, cavernous sinus, and foramen magnum tumors are very rare. Meningiomas constitute a small proportion of reported cases of pediatric skull base pathology, and they are entirely absent from many case series. Initial gross total resection is consistently associated with superior outcomes. Surgical approaches to the pediatric skull base must take additional factors into consideration including relatively smaller anatomy, immature dentition, incompletely aerated sinuses and air cells, and altered configurations of structures such as the pterional bony complex. Multidisciplinary expertise is essential to optimizing treatment outcomes.

A clinical study on survival rate of patients with squamous cell carcinoma of the lower lip in Kosovo

OBJECTIVE

The aim of this study is to find out the survival rate of patients with squamous cell carcinoma of the lower lip in Kosovo and to see the effect of stage of disease on the success of surgical treatment.

PATIENTS AND METHODS

789 patients with SCCLL who were referred to the Department of Maxillofacial Surgery, University Clinical Centre of Kosovo, were examined during a period of 20 years (between 1993 and 2013). 614 (77.82%) of these patients received treatment and have regularly visited the department once every 3 months for post-operative controls. Data have been collected from these 614 patients for 10 years; thus the follow-up period lasts for 10 years for every patient under control. The collected data were analysed using Chi square test. Patients were classified by sex, aetiology, stage of the disease, location of the disease, the treatment patients received, metastasis rate and survival rate.

RESULTS

The most susceptible patients were those at ages between 50 and 70. The youngest patient was 8 years old whereas the oldest was 92. The male-female ratio was 5:1. 57% of the patients had been working outdoors and had been exposed to sunlight. Ten years survival rate for the Stages I, II, III and IV was 91.7%, 83.7%, 28% and 11.4% respectively.

CONCLUSION

It was found that the success of the surgery was closely related with the stage of disease and early diagnosis. Training the relevant parties (i.e., the people, family doctors etc.) on early diagnosis would improve the survival rate.

Sellar and parasellar lesions - clinical outcome in 61 children

OBJECTIVE

To evaluate clinical outcome in a 10-year consecutive series of children operated for sellar and parasellar tumors with special focus on neuropsychology and endocrinology.

PATIENTS AND METHODS

We analyzed 61 children (30 female) under 18 years of age (mean age 9.9, range 1 month-17 years) operated between 2000 and 2010. Medical records were evaluated retrospectively; postoperative histologic diagnoses included 20 craniopharyngiomas, 17 gliomas, 6 pituitary adenomas and 18 rare tumor entities.

RESULTS

Of 61 patients, 58 (95%) were still alive at last follow-up. Three patients died, all due to progression of malignant rhabdoid tumors. Postoperative clinical morbidity consisted of endocrinological (66%), visual (60.7%) and other neurological deficits (55.9%) after a mean follow-up of 44 months. When compared to all other tumor entities in this series, craniopharyngiomas were associated with high rates of gross-total resection (p=0.008), frequent progression of residual tumor (p=0.005) scotomas (p=0.013), persistent diabetes insipidus (p<0.001), and panhypopituitarism (p<0.001). Surgically treated gliomas showed higher rates of motor weakness (p=0.004), double vision (p<0.001), and milder forms of endocrinopathy (single hormone deficits, p=0.02). In general, deterioration in school performance was associated with multiple surgeries (p=0.018) and radiotherapy (p=0.021).

CONCLUSION

Excellent overall survival in these patients is possible, however malignant rhabdoid tumors have a poor prognosis. Aggressive treatment is associated with significant morbidity. Children operated for craniopharyngioma showed an expected high rate of endocrine deterioration, whereas glioma patients had higher incidences of motor weakness and double vision. The treating physicians should be well aware of all these considerable postoperative deficits, especially when facing interdisciplinary management decisions, and for the informed consent discussions with the patient and the parents.

Impact of skull base development on endonasal endoscopic surgical corridors

OBJECT

Scarce morphometric data exist on the developing skull base as a corridor for endonasal endoscopic approaches (EEAs). Furthermore, the impact of skull base lesions on its development has not been assessed. The authors describe a novel set of anatomical parameters characterizing the developmental process as well as the utility of these parameters in preoperative planning and a feasibility assessment of EEAs for neurosurgical treatment of skull base lesions in children.

METHODS

Based on specific MRI sequences in 107 pediatric patients (2-16 years of age) without skull base lesions (referred to here as the normal population), 3 sets of anatomical parameters were analyzed according to age group and sex: drilling distance, restriction sites, and working distance parameters. A separate set of patients undergoing EEAs was analyzed in similar fashion to address the impact of skull base lesions on the developmental process.

RESULTS

The volume of the sphenoid sinus significantly increases with age, reaching 6866.4 mm(3) in the 14-16 years age group, and directly correlates with the pneumatization type (r = 0.533, p = 0.0001). The pneumatization process progresses slowly in a temporal-posterior direction, as demonstrated by the growth trend of the sellar width (r = 0.428, p = 0.0001). Nasal restriction sites do not change significantly with age, with little impact on EEAs. The intercarotid distance is significantly different only in the extreme age groups (3.9 mm, p = 0.038), and has an important impact on the transsphenoidal angle and the intracranial dissection limits (r = 0.443, p < 0.0001). The 14.9° transsphenoidal angle at 2-4 years has a 37.6% significant increase in the 11-13 years age group (p = 0.001) and is highly dependent on pneumatization type. Age-dependent differences between working parameters are mostly noted for the extreme age groups, such as the 8.6-mm increase in nare-vomer distance (p = 0.025). The nare-sellar distance is the only parameter with significant differences based on sex. Skull base lesions induce a high degree of variance in skull base measurements, delaying development and decreasing parameter values. Skull base parameters are interdependent. Nare-sellar distance can be used to assess global skull base development because it highly correlates with the intercarotid distance in both the normal population and in patients harboring skull base lesions.

CONCLUSIONS

Skull base development is a slow, gradual, age-dependent, sex-independent process significantly altering endonasal endoscopic corridors. Preoperative MRI measurements of the pediatric skull base are thus a useful adjunct in choosing the appropriate corridor and in assessing working angles and limits during dissection or reparative surgery. Skull base lesions can significantly impact normal skull base development and age-dependent growth patterns.

Skull base surgery for tumors in children: long-term clinical and functional outcome

OBJECT

Skull base tumors in children are rare but require complex approaches with potential morbidity to the developing craniofacial skeleton, in addition to tumor-related morbidity. Reports of long-term clinical and functional outcome following skull base approaches in children are scarce. The authors report long-term outcome in children with tumors undergoing multidisciplinary skull base surgery.

METHODS

A retrospective analysis was undertaken of children undergoing surgery at a single institution between 1998 and 2008 for benign and malignant lesions of the anterior, middle, or posterior cranial base. Patients with craniopharyngioma, pituitary tumors, and optic glioma were excluded. Histology, surgical morbidity, length of hospital stay, progression-free survival, and adjuvant therapy were recorded. Functional and cognitive outcome was assessed prospectively using the Late Effects Severity Score (LESS).

RESULTS

Twenty-three children ranging in age from 13 months to 15 years underwent skull base approaches for resection of tumors during the study period. The median follow-up duration was 60 months. Tumor types included meningioma, schwannoma, rhabdomyosarcoma, neuroblastoma, angiofibroma, and chordoma. Complete resection was achieved in 12 patients (52%). Thirteen patients (57%) had benign histology. The median hospital stay was 7 days. There were 3 deaths, 1 perioperative and 2 from tumor progression. Two patients had CSF leakage (9%) and 2 developed meningitis. Two children (9%) had residual neurological deficit at last follow-up evaluation. Thirteen (59%) of 22 surviving patients received adjuvant therapy. The majority of the patients remain in mainstream education and 19 of the 20 surviving children have an LESS of 3 or lower.

CONCLUSIONS

Children tolerate complex skull base procedures well, with minimal surgical-related morbidity as well as good long-term tumor control rates and functional outcomes from maximal safe resection combined with adjuvant treatment when required.

Endoscopic endonasal resection of sinonasal and skull base malignancies in children: feasibility and outcomes

BACKGROUND

The aim of this study is to present our experience in treating paediatric sinonasal and skull base malignancies with exclusively endonasal endoscopic approach and measure its feasibility.

METHODS

This study is a retrospective review of seven patients under age of 19 years who have sinonasal and skull base malignancies and treated with endoscopic endonasal approach. The main outcome measures are the surgical resection, complications, survival rate, recurrence and gross facial growth.

RESULTS

Radical tumour resection was achieved in all cases with negative margins; no major complications were observed. Mean follow-up was 65 months and no evidence of recurrences. Facial growth assessment showed no gross changes.

CONCLUSION

In selected cases, endoscopic endonasal approach of paediatric sinonasal and skull base malignancies could be an alternative approach. Despite of our few cases, it showed a feasibility of this technique with satisfactory oncological control. A further collaborative study with larger number is needed to have more valid conclusion.

Clinical guidelines for the management of craniofacial fibrous dysplasia

Fibrous dysplasia (FD) is a non-malignant condition caused by post-zygotic, activating mutations of the GNAS gene that results in inhibition of the differentiation and proliferation of bone-forming stromal cells and leads to the replacement of normal bone and marrow by fibrous tissue and woven bone. The phenotype is variable and may be isolated to a single skeletal site or multiple sites and sometimes is associated with extraskeletal manifestations in the skin and/or endocrine organs (McCune-Albright syndrome). The clinical behavior and progression of FD may also vary, thereby making the management of this condition difficult with few established clinical guidelines. This paper provides a clinically-focused comprehensive description of craniofacial FD, its natural progression, the components of the diagnostic evaluation and the multi-disciplinary management, and considerations for future research.

Skull base reconstruction in the pediatric patient

Tumors of the skull base are rare in children and adolescents and present a complicated management problem for oncologists and surgeons alike. Surgical resection is an integral component of the management of many pediatric neoplasms, especially those that are benign or, though not frankly malignant, are locally invasive. The general principles of skull base reconstruction following tumor ablation are applicable to nearly all patients; the reconstructive algorithm, however, is particularly complex in the pediatric population and the potential benefits of therapy must be balanced against the cumulative impact on craniofacial growth and maturity and the donor site morbidity. A retrospective analysis of all patients less than 19 years of age who underwent resection of a skull base tumor was performed. Particular emphasis was placed on the 12 patients who required complex reconstruction by the plastic surgical service. This represents approximately a third of the operated patients. Data were recorded on patient age, tumor pathology and location, prior therapies, surgical approach, extent of resection, margin status, defect components, details of reconstructive methods employed, complications, additional procedures or interventions, and the use and timing of adjuvant therapies. Patient outcome at most recent follow-up was recorded. All patients were followed clinically and by MRI and/or CT scan of the skull base. The reconstructive details recorded included flap choice, recipient vessels, and any concomitant procedures performed. The indications for and details of any staged surgical revisions or prosthetics were also noted. Complications recorded included partial or total flap loss, cerebrospinal fluid leakage, meningitis, infection, abscess, hematoma or seroma formation, delayed healing, and donor site dysfunction. The vertical rectus abdominis myocutaneous free flap was the most common means of reconstruction utilized in this series. Three of 12 patients had reconstruction related complications. Delayed reconstructive procedures or prosthetic interventions have been performed in 6 of the 12 patients who underwent complex reconstructions. On the basis of our experience and previous reports in the literature, we offer the following guidelines for the successful multidisciplinary care of children and adolescents undergoing skull base reconstruction after tumor resection: (1) skull base reconstruction may be safely performed in children and adolescents using free tissue transfer or local flaps; (2) larger defects and those involving more than one anatomic region of the skull base should be repaired with soft-tissue free flaps; and (3) because of the versatility and reliability of free flaps, pedicled flaps should be reserved for limited defects. Because of the potentially synergistic effects of multimodality treatment for skull base malignancies on craniofacial growth and development, we advocate soft-tissue reconstruction as the primary technique, reserving bony flaps for definitive procedures in survivors who have reached skeletal maturity.

Combined craniofacial resection of anterior skull base tumors: long-term results and experience of single institution

In this article, the authors are presenting their experience and the results with combined craniofacial resection of anterior skull base tumors based on a review of 27 constitutive cases. Our data are evaluated in comparison to other major centers in other parts of the world, and possible factors that might influence surgical outcome and survival are discussed. Twenty-seven patients diagnosed with anterior skull base tumors between 1999 and 2009 were treated by combined craniofacial resection. Of these patients, there were 19 males (70, 3%) and eight females (29, 7%). The age ranged between 11 and 75 years (mean = 45.9 ± 17.6 years). The follow-up period ranged between 14 and 123 months (avarage = 74 months). The most common presenting symptoms were nasal obstruction and vision disturbance (11 patients for each -40.7%). Total resection was achieved in 24 patients (89%), while subtotal resection was done in three patients (11%). The most common complication was CSF fistule with rhinorrhea, which occurred in five patients (18.5%). Eight patients had recurrences at the time of this long-term follow-up. There were two mortalities in the early postoperative period and seven deaths in the long-term follow-up (overall mortality, 33.3%). The overall 5-year overall survival for all patients in our series was 70.4%. The 5-year overall survival was 62% for patients with malignant tumors and 100% for patients with benign tumors. Combined craniofacial resection of tumors of the anterior skull base is an effective approach for the management of these pathologies. The effectiveness is clearly demonstrated by the clinical results and outcomes of these patients' groups. The favorable prognosis is enhanced by significantly by total resection with negative tumor margins.

Proton therapy in chordoma of the base of the skull: a systematic review

Chordoma is a rare, slow-growing, locally aggressive, primary bone tumor that arises from the skull base region in approximately 25-35% of cases. The therapeutic approach to chordoma has traditionally been surgery, followed by radiation therapy. The advent of charged particle radiotherapy has let us consider protons as the postoperative treatment of choice, but no controlled studies have yet confirmed the superiority of protons over photons. During January 2008, two independent researchers conducted a systematic review of the current data on the treatment of base of the skull chordoma C with proton therapy (PT) and, for comparison, with other irradiation techniques (conventional radiation therapy, ion therapy, fractionated stereotactic radiation therapy, and radiosurgery). Two hundred and ten reports in total were retrieved (81 concerning PT). According to the inclusion criteria, 47 articles were considered in the analysis. There were no prospective trials (randomized or nonrandomized) but just seven uncontrolled single-arm studies for PT, providing clinical outcomes for 416 patients in total; these reports were mainly related to advanced inoperable or incompletely resected tumors. The therapeutic approach to chordoma of the base of the skull has traditionally relied on surgical control. Radiation therapy has demonstrated to be a valuable modality for local control in the postoperative setting, particularly with the advent of charged particle radiotherapy. The use of protons has shown better results in comparison to the use of conventional photon irradiation, resulting in the best long-term (10 years) outcome for this tumor with relatively few significant complications considering the high doses delivered with this therapeutic modality.

Spontaneous regression of a vascular tumor of the skull base--infantile hemangioendothelioma?

Extracerebral masses involving the skull base in children and adolescents are rare. We report on a 4-month-old infant who was diagnosed with a large extracerebral mass in the anterior fossa. Subtotal resection to prevent impending blindness was complicated by almost fatal bleeding. Histopathologically, vessel malformation, epitheloid hemangioendothelioma, and angiosarcoma were possible diagnoses. The residual tumor regressed spontaneously and completely within 6 months after surgery. Retrospectively, histologic and radiologic findings and clinical course prompted the diagnosis of an infantile hemangioendothelioma. To our knowledge, this is the first report on an infantile hemangioendothelioma of the skull base.

Tumor-biology and current treatment of skull-base chordomas

Chordomas are rare, slow growing tumors of the axial skeleton, which derive from the remnants of the fetal notochord. They can be encountered anywhere along the axial skeleton, most commonly in the sacral area, skull base and less commonly in the spine. Chordomas have a benign histopathology but exhibit malignant clinical behavior with invasive, destructive and metastatic potential. Genetic and molecular pathology studies on oncogenesis of chordomas are very limited and there is little known on mechanisms governing the disease. Chordomas most commonly present with headaches and diplopia and can be readily diagnosed by current neuroradiological methods. There are 3 pathological subtypes of chordomas: classic, chondroid and dedifferentiated chordomas. Differential diagnosis from chondrosarcomas by radiology or pathology may at times be difficult. Skull base chordomas are very challenging to treat. Clinically there are at least two subsets of chordoma patients with distinct behaviors: some with a benign course and another group with an aggressive and rapidly progressive disease. There is no standard treatment for chordomas. Surgical resection and high dose radiation treatment are the mainstays of current treatment. Nevertheless, a significant percentage of skull base chordomas recur despite treatment. The outcome is dictated primarily by the intrinsic biology of the tumor and treatment seems only to have a secondary impact. To date we only have a limited understanding this biology; however better understanding is likely to improve treatment outcome. Hereby we present a review of the current knowledge and experience on the tumor biology, diagnosis and treatment of chordomas.

Transpalatal endoscopic endonasal resection of a giant epignathus skull base teratoma in a newborn. Case report

Teratomas are neoplasms composed of tissues from all three germ layers with varying degrees of differentiation. They are most commonly found in the sacrococcygeal and gonadal regions and rarely occur in the head and neck region. A teratoma is termed "epignathus" when it arises from the skull base or hard palate and is located in the oral cavity. The authors describe a case of a giant epignathus teratoma originating in the skull base of a neonate, extending bilaterally via two pedicles throughout the hard palate and protruding through the oral cavity. The tumor was completely resected using a transpalatal endoscopic endonasal approach. The excised tumor proved to be an immature teratoma with well-differentiated yolk sac elements. At the 1-year follow-up the patient showed no evidence of tumor recurrence and the child remains neurologically intact. This report demonstrates the use of a transpalatal endonasal corridor in a preterm infant. This approach provided an ample corridor into the ventral skull base without the need for external excisions and/or disruption of osseous elements.

Benign fibrous histiocytoma of the skull base. Case report

The authors report the case of benign fibrous histiocytoma (BFH) of the skull base in an 11-month-old girl. During draining for a middle ear infection, the child was noted to have an anomalous mass in the skull base. On magnetic resonance imaging studies a soft-tissue mass of the skull base primarily involving the regions of the temporal and occipital bones was discovered. Results of a surgical biopsy were consistent with BFH. At the most recent follow-up examination--18 months postoperatively--the child was noted to be asymptomatic with no gross increase in tumor size.

Cranial base strategies for resection of craniopharyngioma in children

The optimal treatment of craniopharyngioma in children remains a challenge. The use of complete excision to minimize recurrence continues to be controversial because of the risk of postoperative morbidity and death. Advances in skull base approaches, modern microsurgical techniques, neuroimaging, and hormone replacement therapy, however, have allowed safe gross- or near-total resection in the majority of cases. Total removal of these tumors, if possible, offers the best chance of cure for the patient. Although craniopharyngiomas are not strictly tumors of skull base origin, their intimate relationship with the neurovascular structures of this region often requires a skull base approach to maximize the surgical corridor and facilitate adequate microsurgical resection. In this review, the authors focus on commonly used skull base approaches for the surgical management of craniopharyngioma. They discuss the relative indications, advantages, disadvantages, and complications associated with each approach. Illustrative cases and intra-operative videos are presented.

Surgical strategies in the removal of malignant tumors and benign lesions of the anterior skull base

The choice of surgical approaches to the tumors of the anterior skull base is determined by the location, dimensions of such lesions and their relations to the surrounding structures. Furthermore, the need for the reconstruction of the dura and skull base structures has an important influence on the decision about the surgical procedure. Transfacial approaches provide limited exposure, especially when tumors damage the floor of the anterior cranial fossa and involve the frontobasal dura and brain. Transcranial, craniofacial and subcranial approaches in particular may aid a surgeon in the removal of such lesions, and often these surgical procedures are the only beneficial methods. Our study comprised 15 patients. Transcranial approaches were used in ten cases. In five further cases, we adopted craniofacial or subcranial approaches. Total removal of these lesions was possible in 13 cases. Neither important complications nor death after surgery was observed except for two cases (craniofacial/subcranial approach) where the CSF leak and CNS infection were reported. We deem that the transcranial approach creates a good possibility for total removal of anterior skull base tumors, particularly of the benign lesions, and permits reconstruction of the skull base damaged by the tumor. However, in patients with large malignant tumors, the en bloc resection via the combined craniofacial/subcranial approach achieved better outcome.