Skull Base Aspergillus Infection Mimicking Tumor Recurrence: A Nasopharyngeal Carcinoma Case Study.

ABSTRACT: We report a case of recurrent nasopharyngeal carcinoma postnasopharyngectomy, presenting with headaches. MRI revealed abnormal signals of the clivus with enhancement, and FDG PET/CT indicated intense uptake in the nasopharynx, clivus, and left neck lymph nodes. Bone SPECT/CT showed bony erosion and uptake in bilateral skull base areas. Biopsy confirmed aspergillosis. Despite the challenges in distinguishing tumor invasion from Aspergillus infection on MRI, bone SPECT/CT, and FDG PET/CT, the short postsurgery period and extensive uptake suggested skull base osteomyelitis.

A Case of Olfactory Neuroblastoma Developing Bilateral Retropharyngeal Lymph Node Metastasis 14-years After Skull Base Surgery.

Olfactory neuroblastoma (ONB) is an uncommon malignant tumor and is usually treated by a multidisciplinary approach includes surgery, radiotherapy, and chemotherapy. A 62 years-old male had a tumor in the nasal cavity and diagnosed as ONB with Kadish A stage. Anterior skull base surgery was performed as radical treatment. Since the surgical margin was negative, no postoperative radiotherapy was administered. 14 years after the surgery, bilateral otitis media with effusion (OME) was occurred, we found the recurrence tumor at bilateral retropharyngeal lymph node (RPLN) which surrounded the internal carotid arteries. Since these were unresectable, we planned chemoradiotherapy which was 70Gy of intensity modulated radiotherapy combined with two courses of carboplatin and etoposide. The tumor volume was reduced and bilateral OME were improved. He has been alive for 3 years after salvage treatment. Although ONB has a relatively good prognosis, it is known to often cause cervical lymph node metastasis. Grades III and IV of Hyams classification are considered high risk. This case, initial tumor was limited in the nasal cavity and its clinical classification was early stage, but Hyams classification was grade III. In reference to this case, considering that RPLN metastasis are difficult to radically resect at the salvage surgery, including this area in postoperative radiotherapy was considered an option.

Granulomatous Inflammation of the Skull Base: A Rare Case of Mycobacterium tuberculosis in the United States.

The differential for an ill-defined, bone-destructive, granulomatous lesion of the skull base includes malignancy, as well as autoimmune and infectious processes. Suspicion for tuberculosis of the skull base in high-risk patients is particularly necessary given the difficulty to culture on standard cultures, need for specific and prolonged antibiotic therapy, and dire morbidity if not diagnosed and treated in a timely manner. Repeat biopsies and cultures were necessary to diagnose this case of Mycobacterium tuberculosis of the skull base after initial biopsy was non-diagnostic. Laryngoscope, 134:4023-4027, 2024.

3-D Printed Skull Model: Role in Identification of Site of Bone Defect in Cases with CSF Rhinorrhea.

Role of 3-D models in the identification of the site and extent of bone defects in the skull base for the treatment of CSF rhinorrhea is analyzed. Such models were used successfully in the management of two patients who failed previous attempts at basal reconstruction. The principal advantage of the models was in exact delineation of the size and site of bone defect and deciphering of its relationship with adjoining critical regions of the brain.

Combined simultaneous endoscopic endonasal and transcranial surgery using high-definition three-dimensional exoscope for malignant tumors of the anterior skull base.

BACKGROUND: Advanced surgical interventions are required to treat malignancies in the anterior skull base (ASB). This study investigates the utility of endoscopic endonasal and transcranial surgery (EETS) using a high-definition three-dimensional exoscope as an alternative to traditional microscopy. METHODS: Six patients with carcinomas of varying histopathologies underwent surgery employing the EETS maneuver, which synchronized three distinct surgical modalities: harvesting of the anterolateral thigh flap, initiation of the transnasal technique, and initiation of the transcranial procedure. RESULTS: The innovative strategy enabled successful tumor resection and skull base reconstruction without postoperative local neoplastic recurrence, cerebrospinal fluid leakage, or neurological deficits. CONCLUSION: The integration of the exoscope and EETS is a novel therapeutic approach for ASB malignancies. This strategy demonstrates the potential of the exoscope in augmenting surgical visualization, enhancing ergonomics, and achieving seamless alignment of multiple surgical interventions. This technique represents a progressive shift in the management of these complex oncological challenges.

Anterior endoscopic sublabial transmaxillary access to middle cranial base lesions.

BACKGROUND: Anterior endoscopic access to middle cranial base lesions becomes feasible in the presence of infratemporal fossa (ITF) involvement. Various approaches, including endoscopic endonasal, transoral sublabial, and transorbital methods, have been described for accessing the ITF through a transmaxillary corridor. Among these approaches, endonasal access is the most commonly preferred, while the transorbital approach is a novel technique gaining popularity. The transoral sublabial approach is considered suitable for selected lesions. METHODS: Patients who underwent the anterior endoscopic transoral/sublabial transmaxillary approach to middle cranial base lesions at a single institute from 2016 to 2023 were included in this retrospective study. Malignant lesions were excluded from the study. The sublabial approach was exclusively performed in all cases, with the exception of one patient who required a combined approach. RESULTS: The anterior endoscopic transoral sublabial transmaxillary approach to the infratemporal fossa, upper parapharyngeal space, and middle cranial fossa was performed on 14 patients. The underlying conditions for these patients were as follows: trigeminal schwannomas (n = 8), meningiomas (n = 2), juvenile nasopharyngeal angiofibroma, osteochondroma, arachnoid cyst and encephalocele (n = 1 each). Gross total resection was achieved in 11 cases. The most common complication was numbness in the territory of the maxillary and mandibular nerves (n = 4). Two patients needed endoscopic maxillary antrostomy for persistent suppuration. No wound problems or CSF rhinorrhea occurred. The average follow-up time was 26.6 months. CONCLUSION: The endoscopic sublabial transmaxillary approach provides direct access to the infratemporal fossa and middle cranial base, enhancing the surgical range of maneuverability while sparing the sinonasal cavity. This procedure is safe, less invasive, and could be used as an efficient corridor for the resection of selected infratemporal fossa lesions with or without extension to the middle cranial base and parapharyngeal space.

[Usefulness of Preoperative Simulation: Skull Base Approach].

Preoperative simulation images creates an accurate visualization of a surgical field. The anatomical relationship of the cranial nerves, arteries, brainstem, and related bony protrusions is important in skull base surgery. However, an operator's intention is unclear for a less experienced neurosurgeon. Three-dimensional(3D)fusion images of computed tomography and magnetic resonance imaging created using a workstation aids precise surgical planning and safety management. Since the simulation images allows to perform virtual surgery, a déjà vu effect for the surgeon can be obtained. Additionally, since 3D surgical images can be used for preoperative consideration and postoperative verification, discussion among the team members is effective from the perspective of surgical education for residents and medical students. Significance of preoperative simulation images will increase eventually.

[Endoscopic Surgery for Skull Base Tumors].

With the development of endoscopic and peripheral instruments, endonasal or transcranial endoscopic surgery for skull-base tumors has become more common. Preoperative simulation makes it relatively easy to understand the anatomical relationship between skull base tumors and the surrounding vital structures, which vary with each case. This may lead to the avoidance of complications and an improvement in the removal rate. Especially in cases of skull base tumors where multiple surgical approaches are possible, the three-dimensional model can be used to confirm the surgical field for each approach and consider the most appropriate. With the development of endovascular treatment and radiotherapy, experience in craniotomy has decreased. Young neurosurgeons need to develop skills to learn as efficiently as possible from their limited experience. Therefore, it is extremely useful to provide an environment that allows for easier preoperative simulations.

Primary Intraosseous Granular Cell Tumor of the Sphenoid and Central Skull Base in a Pediatric Patient.

BACKGROUND: Granular cell tumors occur in all ages and many anatomic sites. In the craniofacial region, they typically arise in soft tissue, not bone. We present a primary intra-osseous granular cell tumor of the sphenoid and central skull base arising in a 12- year- old girl. CASE REPORT: A 12-year-old female with sickle cell disease and Jeavons syndrome presented with seizures. Imaging and partial resection revealed an expansile benign granular cell tumor (GCT) involving the sphenoid body, pterygoid process, and central skull base. The disease has remained stable after 36-month follow up. DISCUSSION: GCT primarily involving the osseous sphenoid/skull base has not been previously reported in a child. Although mostly benign, some are aggressive, with malignant transformation in 1-2%. Surgery is the mainstay of treatment, but in the skull base this may be limited by adjacent critical structures. Decision-making is guided by anatomic extent, histology, and clinical behavior.

Imaging spectrum and complications of otogenic infections: insights into delayed diagnosis.

Skull base osteomyelitis (SBO) is a late manifestation of complicated otogenic infections that presents a diagnostic challenge. Delayed or missed diagnoses lead to high morbidity and mortality and can be attributed to non-specific symptoms, subtle early radiologic findings, radiologic mimicry of nasopharyngeal carcinoma (NPC), and under-recognition from clinician and radiologists. This pictorial review aims to emphasize on early imaging recognition and distinction between SBO and NPC.

An Unknown Foreign laryngeal Object: an exotic complication of skull base osteoradionecrosis.

BACKGROUND: Osteoradionecrosis (ORN) of the skull base is a rare complication after head and neck radiation with a broad variety of subsequent complications. METHODS: A 68-year-old woman with a complex oncological history (right-sided sphenoid meningioma; left-sided neck metastasis of a Cancer of Unknown Primary-CUP) was admitted with a right-sided epi-/ oropharyngeal mass and severe pain exacerbations for further evaluation. CT scan revealed an advanced ORN of the skull base with subsequent abruption of the ventral part of the clivus. This dislocated part of the clivus wedged in the oropharynx for 48 h and then moved towards the larynx, resulting in dyspnea and almost complete airway obstruction. RESULTS: Due to the dangerous airway situation, an urgent exploration and removal of the dislocated clivus was necessary. After a potential cervical spine instability was ruled out, the patient's airway was initially secured with an awake tracheotomy and the clivus was removed transorally. The tracheostomy tube was removed during the ongoing inpatient stay, and the patient was discharged with significant pain relief. CONCLUSIONS: The present case illustrates an orphan complication of skull base ORN resulting in a major airway emergency situation.

[Endoscopic endonasal anterior skull base surgery : Presentation of a monocentric entity profile]. / Endonasal-endoskopische anteriore Schädelbasischirurgie : Darstellung eines monozentrischen Entitätenprofils.

BACKGROUND: Extended endoscopic endonasal surgery (EEES) is an essential part of treatment of various pathologies of the anterior skull base. In addition to significant improvements in the quality of life of affected patients and a lower complication profile compared to open skull base surgery, the therapeutic results are comparable if the indications are correct. MATERIALS AND METHODS: Data of all endoscopic endonasal skull base procedures performed at the University Skull Base Center Hamburg under the direction of the Department of Otorhinolaryngology between June 2018 and November 2022 were retrospectively collected. RESULTS: A total of 50 cases were identified. Of these, 56% (28/50) were malignant tumors, 24% (12/50) were benign pathologies with direct skull base involvement, and 20% (10/50) were anterior skull base defects with rhinoliquorrhea. In 96% (48/50) of cases, the preoperatively set goal of surgery (representative biopsy, complete resection, closure of the skull base defect) could be achieved. Complications grade III or higher according to Clavien-Dindo occurred in 4/50 cases. During the observation period, n = 5 olfactory neuroblastomas were diagnosed, all of which were exclusively and successfully operated on endoscopically. CONCLUSION: In recent years, the spectrum of endoscopically resectable pathologies of the anterior skull base has steadily expanded. In particular, midline-related tumors such as olfactory neuroblastoma or iatrogenic/idiopathic skull base defects with cerebrospinal fluid rhinorrhea are treated completely endoscopically with very good results. Nevertheless, there are also limitations to this technique. Due to high variance in the scope of frontobasal surgery, the extent, and the complex anatomy, as well as the overlapping responsibilities of the specialist disciplines, establishment of certified skull base centers and bundling of frontobasal surgery at these centers is highly relevant for quality assurance.

Primary pulmonary enteric adenocarcinoma presenting as a solitary skull mass.

Pulmonary enteric adenocarcinoma (PEAC) is a rare, aggressive variant of lung adenocarcinoma with early metastatic potential. We present the case of a male smoker in his 50s who presented with right-sided numbness, pain and headache. Imaging revealed a destructive skull base mass invading the right sphenoid sinus. Histopathology was consistent with PEAC. The diagnosis was metastatic PEAC with a distant spread to the skull and represents the first case reported in the literature. We present an associated literature review of the clinical presentation, histological features and management of PEAC with skull metastasis. Metastasis should be considered when evaluating any persistent cranial lesion. Diagnosis requires thorough clinical, radiological and pathological assessment. Treatment involves surgical resection, chemoradiation and targeted therapy. Prognosis directly correlates with clinical stage at presentation. This case highlights the importance of careful evaluation of skull lesions, even in patients without known primary malignancy. Early diagnosis and multimodal therapy may improve outcomes.

Aspergillus infections of lateral skull base: a case series.

PURPOSE: While extensive research with accurate classification has been done in mycoses of the paranasal sinuses and anterior skull base, a similar understanding of lateral skull base fungal pathologies is lacking due to relative rarity and diagnostic difficulties. We introduce a series of eleven cases and two different invasive entities of Aspergillus temporal bone diseases-fungal skull base osteomyelitis (SBO)/malignant otitis externa (MOE) and chronic invasive granulomatous fungal disease (CIGFD). METHODOLOGY: A retrospective observational study was conducted at the neuro-otology unit of a tertiary care referral center between July 2017 and November 2022. Diagnosed cases of lateral skull base osteomyelitis with atypical symptoms and lack of response to culture-directed antibiotics were evaluated for fungal origin. Patient data, including history, laboratory findings, serum galactomannan assay, CT and MRI imaging findings, clinical examination findings, and co-morbidities, were analyzed. The treatment course and response were assessed. RESULTS: A total of 11 cases were included in the study. Of these, 9 were cases of Aspergillus-induced skull base osteomyelitis (SBO) and 2 of Aspergillus-induced chronic invasive granulomatous fungal disease (CIGFD). CIGFD presented with persistent ear discharge and slowly progressive post-aural swelling, while all patients of fungal SBO had lower cranial nerve palsies. CIGFD responded to excision and antifungals, while SBO responded well to conservative anti-fungal treatment. CONCLUSION: In cases of lateral SBO not responding to antibiotic therapy, the possibility of fungal etiology should be considered. Aspergillus spp. seems to be the major fungal pathogen.

Extent of Surgical Resection as a Predictor of Tumor Progression in Skull Base Chordomas: A Multicenter Volumetric Analysis.

INTRODUCTION: Skull-base chordomas are aggressive tumors with a propensity for recurrence/progression. Even with standard of care (SoC), 5-year recurrence rates are variable (19%-54%). This high recurrence/progression rate correlates with increased morbidity and mortality. We sought to analyze a multicenter cohort of skull base chordomas to identify predictors of progression in patients receiving SoC. METHODS: The [Blinded]-Neurosurgery data registry was queried for skull base chordomas treated from 2008-2020. Patients with the histopathologic diagnosis of chordoma were included. The cohort was composed of patients with preoperative and postoperative magnetic resonance imaging. Tumor volume and radiologic characteristics were obtained from axial T2 sequences using a Digital Imaging and Communications in Medicine viewer. Survival analysis was performed using Kaplan-Meier method, and time-to-event multivariate regression was performed to identify independent predictors of progression. RESULTS: The cohort included 195 patients, of which 66 patients met inclusion criteria; median age was 44, and 28 (42%) were females. Fifty-four (82%) received SoC, 7 (11%) resection only, and 5 (8%) radiotherapy only. Median preoperative and postoperative tumor volumes were 11.55 cm3 (0.33-54.89) and 0.34 cm3 (0-42.52), respectively. Recurrence rate with SoC was 37%. Postoperative tumor volume (P = 0.010) correlated with progression. A postoperative volume of >4.9 cm3 (P = 0.044), ≤81.3% of tumor resection (P = 0.02), and lower-clivus location (P < 0.005) correlated with decreased time to progression. CONCLUSIONS: Skull base chordomas can be challenging to resect. Even though maximal resection and radiotherapy improve rate of tumor progression, many of these lesions eventually recur. We have identified a postoperative tumor volume of ≥4.9 cm3 and extent of resection of ≤81.3% in this cohort as predictors of progression in patients receiving SoC.

Incidence of postoperative hyponatremia after endoscopic endonasal pituitary transposition for skull base pathologies.

PURPOSE: Pituitary transposition is a novel surgical approach to access the retroinfundibular space and interpeduncular cistern. Few studies have evaluated post-surgical outcomes, including incidence of hyponatremia, following pituitary transposition. METHODS: This is a retrospective study including 72 patients who underwent endoscopic endonasal surgery involving pituitary transposition for non-pituitary derived tumors over a decade at the University of Pittsburgh Medical Center. Anterior pituitary deficiencies and replacement therapy, tumor pathology and pre-operative serum sodium (Na) were recorded. Na was assessed at postoperative day 1, 3, 5, 7, and 10. Anatomical/surgical parameters included sellar height, sellar access angle to approach the tumor, and cranial extension of the tumor above the sellar floor (B) compared to the height of the gland (A) (B/A). T-test (normally distributed variables) and Wilcoxon rank-sum test (not-normally distributed) were applied for mean comparison. Logistic regression analyzed correlations between anatomical/surgical parameters and postoperative hyponatremia. RESULTS: 55.6% of patients developed post-operative transient hyponatremia. Two patients (5%) developed severe hyponatremia (sodium level < 120 mmol/L). Eleven (15.3%) patients required desmopressin replacement immediately post-operatively, and 2 other patients needed desmopressin after discharge and after sodium nadir developed. Hyponatremia was inversely associated with sellar access angle (p = 0.02) and the tumor cranial extension above the sellar floor showing a trend towards significance (p = 0.09). CONCLUSION: More than half of patients who had pituitary transposition developed transient hyponatremia. Hyponatremia was more common in those with narrower sellar access angle and smaller cranial extension of the tumor above the sellar floor. Anatomical/surgical parameters may allow risk-stratification for post-operative hyponatremia following pituitary transposition.

Skull Base Tumors.

OBJECTIVE: This article reviews the presenting features, molecular characteristics, diagnosis, and management of selected skull base tumors, including meningiomas, vestibular schwannomas, pituitary neuroendocrine tumors, craniopharyngiomas, chordomas, ecchordosis physaliphora, chondrosarcomas, esthesioneuroblastomas, and paragangliomas. LATEST DEVELOPMENTS: Skull base tumors pose a management challenge given their complex location and, as a result, the tumors and treatment can result in significant morbidity. In most cases, surgery, radiation therapy, or both yield high rates of disease control, but the use of these therapies may be limited by the surgical accessibility of these tumors and their proximity to critical structures. The World Health Organization classification of pituitary neuroendocrine tumors was updated in 2022. Scientific advances have led to an enhanced understanding of the genetic drivers of many types of skull base tumors and have revealed several potentially targetable genetic alterations. This information is being leveraged in the design of ongoing clinical trials, with the hope of rendering these challenging tumors treatable through less invasive and morbid measures. ESSENTIAL POINTS: Tumors involving the skull base are heterogeneous and may arise from bony structures, cranial nerves, the meninges, the sinonasal tract, the pituitary gland, or embryonic tissues. Treatment often requires a multidisciplinary approach, with participation from radiation oncologists, medical oncologists, neuro-oncologists, and surgical specialists, including neurosurgeons, otolaryngologists, and head and neck surgeons. Treatment has largely centered around surgical resection, when feasible, and the use of first-line or salvage radiation therapy, with chemotherapy, targeted therapy, or both considered in selected settings. Our growing understanding of the molecular drivers of these diseases may facilitate future expansion of pharmacologic options to treat skull base tumors.

[EXTENDED ENDONASAL ENDOSCOPIC APPROACH IN TREATING PITUITARY ADENOMAS AND SKULL BASE TUMORS].

INTRODUCTION: The endoscopic endonasal approach (EEA) is a rapidly growing, minimally invasive discipline applied to a broad set of skull base tumors. The introduction of the endoscopic endonasal approach for the management of lesions of the skull base has produced a paradigm shift in the way these complicated lesions are managed. The extended endonasal approach provides the most direct route to the anterior cranial base including sella, cribriform plate, planum sphenoidale, suprasellar cistern, clivus and foramen magnum. Transsphenoidal microscopic pituitary surgery has long been considered the gold standard in surgical treatment of pituitary tumors. Extended endonasal endoscopic pituitary surgery has come into prominence over the last two decades as a superior alternative to microscopic surgery. Gaining experience in this approach has allowed the use of EEA for the surgical treatment of more complex pathologies such as meningiomas, craniopharyngiomas and more.

Unravelling the role of immune cells and FN1 in the recurrence and therapeutic process of skull base chordoma.

BACKGROUND: Skull base chordoma is a rare and aggressive tumour of the bone that has a high likelihood of recurrence. The fundamental differences in single cells between primary and recurrent lesions remain poorly understood, impeding development of effective treatment approaches. METHODS: To obtain an understanding of the differences in single cells between primary and recurrent chordomas, we performed single-cell RNA sequencing and T-cell/B-cell receptor (BCR) sequencing. This allowed us to delineate the differences between the two types of tumour cells, tumour-infiltrating lymphocytes, myeloid cells, fibroblasts and B cells. Copy number variants (CNVs) were detected and compared between the tumour types to assess heterogeneity. Selected samples were subjected to immunohistochemistry to validate protein expression. Fluorescence in situ hybridisation experiments, Transwell assays and xenograft mouse models helped verify the role of fibronectin 1 (FN1) in chordoma. RESULTS: Promoting natural killer (NK) cell and CD8_GZMK T-cell function or inhibiting the transformation of CD8_GZMK T cells to CD8_ZNF683 T cells and promoting the transformation of natural killer T (NKT) cells to NK cells are promising strategies for preventing chordoma recurrence. Additionally, inhibiting the M2-like activity of tumour-associated macrophages (TAMs) could be an effective approach. Antigen-presenting cancer-associated fibroblasts (apCAFs) and dendritic cells (DCs) with high enrichment of the antigen-presenting signature were enriched in primary chordomas. There were fewer plasma cells and BCR clonotypes in recurrent chordomas. Remarkably, FN1 was upregulated, had more CNVs, and was more highly secreted by tumours, macrophages, CD4 T cells, CD8 T cells and fibroblasts in recurrent chordoma than in primary chordoma. Finally, FN1 enhanced the invasion and proliferation of chordomas in vivo and in vitro. CONCLUSION: Our comprehensive picture of the microenvironment of primary and recurrent chordomas provides deep insights into the mechanisms of chordoma recurrence. FN1 is an important target for chordoma therapy.