Extracranial Extension Research Articles

Preservation of cranial nerve function in large and giant trigeminal schwannoma resection: a case series.

Trigeminal schwannomas (TSs) are intracranial tumors that can cause significant brainstem compression. TS resection can be challenging because of the risk of new neurologic and cranial nerve deficits, especially with large (≥ 3cm) or giant (≥ 4cm) TSs. As prior surgical series include TSs of all sizes, we herein present our clinical experience treating large and giant TSs via microsurgical resection. This was a retrospective, single-surgeon case series of adult patients with large or giant TSs treated with microsurgery in 2012-2023. Seven patients underwent microsurgical resection for TSs (1 large, 6 giant; 4 males; mean age 39 ± 14years). Tumors were classified as type M (middle fossa in the interdural space; 1 case, 14%), type ME (middle fossa with extracranial extension; 3 cases, 43%), type MP (middle and posterior fossae; 2 cases, 29%), or type MPE (middle/posterior fossae and extracranial space; 1 case, 14%). Six patients were treated with a frontotemporal approach (combined with transmastoid craniotomy in the same sitting in one patient and a delayed transmaxillary approach in another), and one patient was treated using an orbitofrontotemporal approach. Gross total resection was achieved in 5 cases (2 near-total resections). Five patients had preoperative facial numbness, and 6 had immediate postoperative facial numbness, including two with worsened or new symptoms. Two patients (28%) demonstrated new non-trigeminal cranial nerve deficits over mean follow-up of 22months. Overall, 80% of patients with preoperative facial numbness and 83% with facial numbness at any point experienced improvement or resolution during their postoperative course. All patients with preoperative or new postoperative non-trigeminal tumor-related cranial nerve deficits (4/4) experienced improvement or resolution on follow-up. One patient experienced tumor recurrence that has been managed conservatively. Microsurgical resection of large or giant TSs can be performed with low morbidity and excellent long-term cranial nerve function.

Surgical management of large lower cranial nerves schwannomas: long term results of a less aggressive resection strategy.

In an effort to reduce the high morbidity and life-threatening complications after radical resection in large schwannoma surgery, alternative strategies of nontotal resections have emerged. To evaluate the long term clinical and oncological outcome after lower cranial nerves (LCN) schwannoma surgery operated on with a cranial nerve-sparing technique. Single center retrospective cohort study of 8 consecutive patients harboring LCN schwannomas operated on between March 2005 and October 2021. The mean LCN schwannoma diameter was 33mm (range 26-51). Seven patients (87,5%) underwent a modified retrosigmoid approach. Three patients underwent gross total resection (37,5%), 3 had received neartotal resection (mean tumor residue 0,25cc) and subtotal resection in 2 patients who presented with an extracranial extension of the tumor (mean tumor residue 2,44cc). Both patients had received upfront additional GKRS. The three patients who presented with preoperative CN IX & X injuries recovered within 6months after surgery. All of the five patients freed from any preoperative CNs IX & X symptoms experienced transient (80%) or definitive (one patient) disturbances after surgery. They all improved within 6months but one who required long term gastrostomy feeding tube. This patient harbored a schwannoma originating from the glossopharyngeal nerve, which could not be anatomically preserved during surgery. Tumor control was achieved in 100% of cases with a mean follow-up of 91months. LCN schwannomas could be surgically removed through a less aggressive non-radical resection strategy with acceptable functional results and excellent tumor control.

Anaesthetic Challenges in a Pediatric with Solitary Fibrous Tumour in the Neck Posted for Resection -A Case Report

Context: Hemangiopericytoma and Solitary fibrous tumor in infant are more vascular involving head and neck region. Juvenile form have better prognosis compared to adult form , so surgical excision offers benefit at this age. Case Report: Ten year old female child had presented with a soft tissue mass in the right temporal region behind ears , which was progressive in growth. In further evaluation, MRI showed heterogenicity enhancing lesion in posterior fossa in right cerebellar region with extracranial extension into subcutaneous space . Histologically, a hypercellular spindle cell mesenchymal neoplasm seen. Conclusion: Solitary Fibrous Tumour of head and neck can grow rapidly during the paediatric age group period. Complete excision without mutilating surgery should be curative.

Surgical Treatment of Malignant Peripheral Nerve Sheath Tumor of the Scalp With Intracranial and Extracranial Extension: A Rare Case Report.

Malignant peripheral nerve sheath tumors of the scalp are rare neoplasms of the peripheral nervous system. Here, we describe an unusual malignant peripheral nerve sheath tumor of the scalp in an 84-year-old Asian man. The tumor was associated with bony destruction, intracranial, and extracranial extension. Trans-arterial embolization was done twice preoperatively. En block excision was performed and the dura and soft tissue defect were reconstructed by anterolateral thigh free fasciocutaneous flap. There is no recurrence and the wound healed well during follow-up.

A rare case report: giant meningioma with extracranial extension

Background: Meningioma is the most frequently occurring primary central nervous system (CNS) tumor, and it is typically found during brain imaging. It has a prevalence of 53 per 100,000 people. Extracranial extension in skull-base meningioma is rare and presents a female preponderance Case Description: We presented an Indonesian female who underwent a brain MRI depicting atypical giant meningioma with extracranial extension. The surgery was conducted, and pathological examination confirmed as a typical meningioma WHO grade I. Recognizing and identifying the entity's unique imaging characteristics are paramount in successfully diagnosing and initiating the most effective treatment. Conclusion: This report is expected to help diagnose giant meningioma, which is a rare case, thus reducing the occurrence of misdiagnosis.

DEK::AFF2 fusion-associated sinonasal carcinoma: A challenging entity mimicking sinonasal papilloma

Abstract Introduction/Objective DEK::AFF2 fusion-associated sinonasal carcinoma (DEK::AFF2 SC) also reported in the literature as low-grade papillary sinonasal carcinoma (LGPSC) is a rare, bland-appearing, but locally aggressive neoplasm. Morphologically, these tumors can closely resemble sinonasal papilloma (SP), leading to misdiagnosis. DEK::AFF2 SC is devoid of the underlying EGFR or KRAS driver mutations of SP, suggesting it represents a distinct unique entity. Herein, we present a case of DEK::AFF2 SC in a 65-year-old female who was repeatedly diagnosed as recurrent/atypical SP over ten years. Methods/Case Report We first encountered our patient in 2015 when she presented for endoscopic removal of recurrent SP, her fifth recurrence since 2011. From 2015-2021, she experienced four additional recurrences which were repeatedly diagnosed as atypical SP until 2021, when a diagnosis of LGPSC was favored. Imaging (in 2015) also revealed a concurrent mastoid sinus mass with extra-cranial extension to the sigmoid sinus with bone erosion. With each recurrence, imaging showed bone erosion and pushing growth, concerning for malignancy. The current (2023) imaging showed mass extending through mastoid process into the posterior cranial fossa. Over the years, all specimens from the nasal cavity, maxillary sinus, mastoid process, and middle ear revealed confluent, bland- appearing, papillary exophytic and inverted growth of squamous epithelium forming cords, trabeculae, and nests. Neutrophilic infiltrate was more prominent interstitially than within the surface epithelium. No brisk mitoses, pleomorphism, or frank stromal invasion was identified. The tumor cells were CK5/6 and p63 immunoreactive. Ki-67 labeling index was low (~10%). Despite receiving chemo-radiotherapy, LGSPC recurred in 2023, and DEK::AFF2 fusion was identified by fluorescence in-situ hybridization. Results (if a Case Study enter NA) NA Conclusion This case highlights the challenges in diagnosing DEK::AFF2 SC. DEK::AFF2 SC should be considered in cases of recurrent/atypical SP, especially those exhibiting destructive growth patterns. The identification and association of DEK::AFF2 fusion in sinonasal carcinomas suggests the potential for targeted therapies, emphasizing the importance of early recognition. Future research is needed to explore the utility of targeted therapy in DEK::AFF2 SC management.

P17.08.A CLINICAL AND MOLECULAR CHARACTERIZATION OF EXTRACRANIAL METASTASES IN GLIOBLASTOMAS

Abstract BACKGROUND Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults, but in contrast to many other malignancies they rarely metastasize. Metastasizing GBMs cause both diagnostic and therapeutic challenges and are generally poorly investigated. Therefore, our aim was to characterize these tumors clinically and molecularly. MATERIAL AND METHODS We collected and examined the largest cohort to date of tissue from 16 glioma patients (14 GBMs and 2 lower-grade gliomas) with extracranial metastases, including metastases to scalp (7) lymph nodes (5), bone (2), liver (1), and upper neck (1). After histopathological re-evaluation of the tumors, we assessed the associated magnetic resonance imaging (MRI) scans. Paired samples from the primary tumors, recurrences and metastases were investigated by next-generation sequencing (NGS) analysis with the TSO500 panel, genome-wide 850 K methylation profiling and immunohistochemistry followed by artificial intelligence-based quantification of markers of stemness and immune cells in the tumor microenvironment (TME). RESULTS Clinically, the patients were comparable to other GBM patients (gender, age, treatment, and survival). 12/16 patients developed one or more intracranial recurrence(s). MRI scans revealed proximity of the brain tumors to dura, large vessels, and ventricles in a high proportion of the patients. Moreover, we found that (6/7) scalp lesions were in fact extracranial extensions of the brain tumors. NGS data showed that the metastases were clonally derived from the primary tumors and not from the brain recurrences. Methylation- and copy number analysis overall confirmed the initial diagnoses and revealed a patient-specific signature across paired samples in a majority of the patients. Additionally, we observed methylation subclass switch during tumor progression and identified differentially methylated regions enriched in the olfactory transduction pathway when comparing metastases to primary tumors. Levels of tumor stemness were generally preserved according to methylation-based stemness index and OLIG2 and SOX2 protein expression. Similarly, the composition of immune cells in the TME did not change significantly, as shown by cell-type deconvolution and immune cell quantification. CONCLUSION Extracranial metastases occurred as early events and overall preserved the tumor- and TME characteristics of the primary brain tumors. Factor such as brain tumor location, neurosurgery and epigenetic regulation of genes associated with olfactory transduction could be involved in glioblastoma metastasis.

Clinicopathological and Neuroimaging Features of Primary Gliosarcoma: A Case Series and Review of Literature

Gliosarcoma (GS) is a rare primary high-grade brain neoplasm with a poor prognosis and challenging surgical resection. Although it is now considered a morphologic variant of IDH-wildtype glioblastoma (World Health Organization Classification of Tumours 2021), GS may display peculiarities that hamper both surgical and oncological management. In this retrospective study, we searched our registry for histologically confirmed GS patients between 2006 and 2020. Cases were reviewed for clinical information, pathologic characteristics, imaging findings, management, and outcome. 21 patients with histologically confirmed GS were identified with a median age of 62years. Twelve were men and 9 women. The temporal lobe was the most common location (9 patients, 42.9%). Nineteen patients underwent surgical resection, and only 4 (19%) demonstrated gross total resection on postsurgical MRI, with an overall median survival of 7months (range, 0.5-37). Diagnostic MRI demonstrated heterogenous lesions with necrotic-cystic areas and a ring-enhancement pattern. Only 1 case of extracranial extension was seen in our sample, and no patient showed distant metastases. The rarity of primary GS and the absence of specific therapeutic guidelines represent a significant clinical challenge. Our study provides a comprehensive analysis of clinical and neuroimaging characteristics in a real-world patient cohort and compares our findings with the available literature.

The Anterolateral Approach, Revisited for Benign Jugular Foramen Tumors With Predominant Extracranial Extension: Microsurgical Anatomy and Case Series (SevEN-012).

The anterolateral approach (ALA) enables access to the mid and lower clivus, jugular foramen (JF), craniocervical junction, and cervical spine with added anterior and lateral exposure than the extreme lateral and endoscopic endonasal approach, respectively. We describe the microsurgical anatomy of ALA with cadaveric specimens and report our clinical experience for benign JF tumors with predominant extracranial extension. A stepwise and detailed microsurgical neurovascular anatomy of ALA was explored with cadaveric specimens. Then, the clinical results of 7 consecutive patients who underwent ALA for benign JF tumors with predominant extracranial extension were analyzed. A hockey stick skin incision is made along the superior nuchal line to the anterior edge of the sternocleidomastoid muscle (SCM). ALA involves layer-by-layer muscle dissection of SCM, splenius capitis, digastric, longissimus capitis, and superior oblique muscles. The accessory nerve runs beneath SCM and is found at the posterior edge of the digastric muscle. The internal jugular vein (IJV) is lateral to and at the level of the accessory nerve. The occipital artery passes over the longissimus capitis muscle and IJV and into the external carotid artery, which is lateral and superficial to IJV. The internal carotid artery (ICA) is more medial and deeper than external carotid artery and is in the carotid sheath with the vagus nerve and IJV. The hypoglossal and vagus nerves run along the lateral and medial side of ICA, respectively. Prehigh cervical carotid, prejugular, and retrojugular surgical corridors allow deep and extracranial access around JF. In the case series, gross and near-total resections were achieved in 6 (85.7%) patients without newly developed cranial nerve deficits. ALA is a traditional and invaluable neurosurgical approach for benign JF tumors with predominant extracranial extension. The anatomic knowledge of ALA increases competency in adding anterior and lateral exposure of extracranial JF.

DUMBBELL-SHAPED HYPOGLOSSAL SCHWANNOMA- A RARE CASE REPORT FROM NORTHEAST INDIA WITH REVIEW OF LITERATURE

Background: Hypoglossal nerve schwannomas are uncommon, benign, and slow growing tumors arising from Schwann cells of the peripheral nerve sheath. They are well-documented in adult population. To the best of our knowledge, dumbbell-shaped hypoglossal schwannomas are rare and only 40 cases have been described in literature till date. They are managed surgically which poses signicant challenges including preservation of facial nerve. A 57 year old female presented with periodic spells of headache Case presentation: , imbalance while walking, trouble swallowing, right-sided tongue atrophy, and chronic chest infection. She was subsequently diagnosed with right cerebello-pontine (CP) angle hypoglossal schwannoma with extracranial extension. The tumor was managed by surgery and was performed in two stages: Stage one involved right retromastoid-sub occipital (RMSO) craniectomy with gross total excision of the lesion in the right CP angle followed by endoscopic assisted transoral-transpharyngeal excision of the tumor in the neck. Post-surgery, the patient showed gradual improvement. She could walk independently, her headache sub-sided and she showed slow improvement of lower cranial nerve function. However, during last follow up, it was observed that atrophy on the right side of the tongue still persisted. This case highlights t Conclusion: he importance of accurate diagnosis and treatment of hypoglossal schwannoma. Complete surgical excision is the recommended treatment for hypoglossal schwannoma which subsequently lowers the risk of recurrence and gives a good prognosis

Extensive extracranial growth of spheno-orbital meningioma: illustrative case.

Spheno-orbital meningioma (SOM) typically presents with a classic triad of symptoms (i.e., proptosis, visual impairment, and ocular paresis), resulting from intraorbital tumor invasion. The authors present a very rare case of SOM in which the chief complaint was swelling of the left temporal region, which, to the best of their knowledge, has not been reported previously. The patient presented with marked extracranial extension to the left temporal region but unremarkable intraorbital extension, even on radiological examination. Physical examination of the patient showed almost no exophthalmos or restriction of left eye movement, consistent with the radiological findings. Four separate meningioma specimens were removed by extraction (i.e., one each from the intracranial, extracranial, and intraorbital segments of the tumor and one from the skull). The World Health Organization grade was 1 and the MIB-1 index was less than 1%, indicating a diagnosis of a benign tumor. SOM may be present even in patients with only temporal swelling and few ocular-related symptoms, and detailed imaging evaluations may be required to identify the tumor.

Ekstrakraniyal uzanımı olan menengiomların tedavisinin zorlukları: Klinik çalışma

Objective: Surgical treatment of extracranial meningiomas is challenging. In this study, we present an illustrated case series to share our experience in the treatment of meningiomas with extracranial extension.
 
 Method: We retrospectively reviewed the data of 11 patients with meningiomas who underwent surgical treatment between 2008 and 2020. The intracranial and extracranial components were radiologically and intraoperatively confirmed for all patients.
 
 Results: The patients included seven men and four women with a mean age of 55.4 years. Most patients presented with facial disfigurement or asymmetrical skull growth. The most common symptom at presentation was headache. The most common location of the meningiomas was the frontal region and those of extracranial growth were the paranasal sinuses and parietal bone invasion. We recognized two distinct modalities of bone destruction: hyperostosis (n=3) and osteolysis (n=8). Pathological investigation revealed atypical features in six patients. Preoperative embolization was attempted in four patients but it proved to be difficult; proper embolization could be achieved only in one patient. The most commonly encountered challenges during surgery were large calvarial and cranial base defects due to bone erosion, dural defects, and managing the superior sagittal sinus with parietal tumors. Excessive blood loss was also of particular concern, which was managed using simple scalp clips, intraoperative transfusion, and other conservative approaches of tumor extensions into paranasal sinuses. No perioperative mortality occurred. Calvarial reconstruction was performed with polymethyl methacrylate cement where needed.
 
 Conclusion: Meningiomas with extracranial extension are surgically challenging but treatable. It contains fine neurosurgical trics in its treatment and follow-up.

Management of Skull-Base Meningiomas With Extracranial Extensions: Clinical Features, Radiological Findings, Surgical Strategies, and Long-Term Outcomes.

Objectives:The aim of this research was to summarize the clinical and prognostic features of the skull-base meningiomas with extracranial extensions, and enhance the management of skull-base communicative meningiomas.MethodsWe retrospectively studied the medical records and analyzed the follow-up information of 53 patients who have done surgery for skull-base meningiomas with extracranial extensions in West China Hospital of Sichuan University from 2009 to 2020.ResultsThe incidence of skull-base meningiomas with extracranial extensions was 0.74%. The average diagnosis age was 45.9 years, with a 1:3.1 men to women ratio. WHO grade I was seen in 84.9% of patients, and higher grades were found in 15.1%. Heterogeneous enhancement, high bone invasion rate, high incidence of peritumoral edema, and high dural tail sign rate were typical imaging features. Routine craniotomy and endoscopic endonasal approach were adopted, and gross total resection was performed in 62.3% of cases with 20.8% postoperative complication rates. The average follow-up time was 61.5 months, with a recurrence rate of 34.9%. By survival analysis, the extent of resection (p = 0.009) and the histological grade (p = 0.007) were significantly related to the prognosis. Adjuvant radiotherapy proved beneficial in patients with subtotal resection (p = 0.010) and high-grade meningiomas (p = 0.018).ConclusionsSkull-base meningiomas with extracranial extensions were sporadic. According to the tumor location and communication way showed by the preoperative imaging, routine craniotomy or endoscopic endonasal approach with a reasonable skull-base repair strategy could be adopted to achieve the maximum tumor resection. Maximized resection, adjuvant radiotherapy, and low histological grade indicate a better prognosis.

Resection of Skull Base Meningioma With Extensive Extracranial Extension: 2-Dimensional Operative Video.

Jugular foramen meningiomas are rare tumors with distinguishing clinical, radiological, and surgical considerations.1,2 They involve the lower cranial nerves, invade the temporal bone, occlude jugular vein and sigmoid sinus, and involve internal carotid and vertebral arteries. Their location is prime for an extensive extracranial cervical extension. They might reach giant size with extension from the Meckel cave in the cerebellopontine angle to the carotid bifurcation in the neck while exhibiting only minor symptoms. Surgical morbidity is associated mainly with lower cranial nerves deficits. Radical surgical removal has been considered impossible with vascular encasement and is associated with a considerable risk of vascular injury. With careful and thorough preoperative evaluation, including evaluating the adequacy of the cerebral collateral and applying an appropriately tailored skull base approach,3 radical tumor resection can be achieved with the expectation of a good outcome.3,4 Meticulous microsurgical dissection of the tumor involving the internal carotid artery in the neck would permit radical resection without vascular damage and avoiding the need for vascular reconstruction.5 We demonstrate this technique in a 47-year-old female patient presented in the year 2007 having a giant jugular fossa tumor with extensive neck extension who consented to surgery. Image at 2:23 reused with permission from Al-Mefty O, Teixeira A. Complex tumors of the glomus jugulare: criteria, treatment, and outcome. J Neurosurg. 2002;97(6):1356-1366, by permission from JNSPG. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_vf9v0duk"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]}

Primary Intraosseous Osteolytic Meningioma with Aggressive Clinical Behaviour: Clinico-Pathologic Correlation and Proposed New Clinical Classification.

(1) Introduction: Primary intraosseous osteolytic meningiomas (PIOM) are non-dural-based tumors predominantly presenting an osteolytic component with or without hyperostotic reactions. They are a subset of primary extradural meningiomas (PEM). In this study, we present a peculiar case with a systematic literature review and propose a new classification considering the limitations of previous classification systems. (2) Materials and Methods: Using a systematic search protocol in Google Scholar, PubMed, and Scopus databases, we extracted all case studies on PIOM published from inception to December 2020. A 46-year-old female patient form Dhaka, Bangladesh, was also described. The search protocol was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. (3) Results: Here, we present a 46-year-old female patient with PIOM who successfully underwent bifrontal craniotomy and gross total removal (GTR) of the tumor. At 6-month follow-up, no tumor recurrence was shown. Including our new case, 55 total cases from 47 articles were included in the analysis. PIOMs were in closer frequency among males (56.4%) and females (43.6%). The most common tumor location was the frontal and parietal calvarium, most commonly in the frontal bone (29.1%). Surgical resection was the predominant modality of treatment (87.3%); only 1.8% of patients were treated with radiotherapy, and 5.4% received a combination of surgery and radiotherapy. Gross total resection (GTR) was achieved in 80% of cases. Extracranial extension was reported in 41.8% of cases, dural invasion in 47.3%, and recurrence in 7.3%. Whole-body 68 Ga-DOTATOC PET/CT has also been reported as a useful tool both for differential diagnosis, radiotherapy contouring, and follow-up. Current treatments such as hydroxyurea and bevacizumab have variable success rates. We have also suggested a new classification which would provide a simple common ground for further research in this field. (4) Conclusions: Surgical resection, especially GTR, is the treatment of choice for PIOM, with a high GTR rate and low risk of complications and mortality. More research is needed on the differential diagnosis and specific treatment of PIOM.

En plaque tuberculoma of the dura with extracranial extension in an adolescent mimicking an aggressive en plaque meningioma

Abstract Tuberculosis has been called the “great mimic.” We present an uncommon case of an en plaque dural tuberculoma in an adolescent that was both causing mass effect intracranially and eroding the skull and extending extracranially mimicking an aggressive meningioma and discuss the theories about the origin of dural tuberculomas, enumerate common radiological differential diagnosis and mention ways that may help to identify the disease without recourse to surgery.

Augmented Reality-Assisted Craniotomy for Parasagittal and Convexity En Plaque Meningiomas and Custom-Made Cranio-Plasty: A Preliminary Laboratory Report.

Background: This report discusses the utility of a wearable augmented reality platform in neurosurgery for parasagittal and convexity en plaque meningiomas with bone flap removal and custom-made cranioplasty. Methods: A real patient with en plaque cranial vault meningioma with diffuse and extensive dural involvement, extracranial extension into the calvarium, and homogeneous contrast enhancement on gadolinium-enhanced T1-weighted MRI, was selected for this case study. A patient-specific manikin was designed starting with the segmentation of the patient’s preoperative MRI images to simulate a craniotomy procedure. Surgical planning was performed according to the segmented anatomy, and customized bone flaps were designed accordingly. During the surgical simulation stage, the VOSTARS head-mounted display was used to accurately display the planned craniotomy trajectory over the manikin skull. The precision of the craniotomy was assessed based on the evaluation of previously prepared custom-made bone flaps. Results: A bone flap with a radius 0.5 mm smaller than the radius of an ideal craniotomy fitted perfectly over the performed craniotomy, demonstrating an error of less than ±1 mm in the task execution. The results of this laboratory-based experiment suggest that the proposed augmented reality platform helps in simulating convexity en plaque meningioma resection and custom-made cranioplasty, as carefully planned in the preoperative phase. Conclusions: Augmented reality head-mounted displays have the potential to be a useful adjunct in tumor surgical resection, cranial vault lesion craniotomy and also skull base surgery, but more study with large series is needed.

PRIMARY EXTRACRANIAL MENINGIOMA OF THE MANDIBLE: A CASE REPORT AND LITERATURE REVIEW OF THIS RARE PRESENTATION

Meningiomas are common benign neoplasms developing within the central nervous system and arise from the meningothelial cells. Extracranial (ectopic) meningiomas are rare and may represent an extracranial extension of an intracranial meningioma or distant metastasis from a primary intracranial meningioma, or they may originate from arachnoid cells in the sheaths of the cranial nerves that are exiting the skull through the foramina or sutures. Ectopic meningiomas can also arise as true primary extracranial meningiomas originating from ectopic arachnoid lining cells or multipotential mesenchymal cells. Primary extracranial meningiomas occurring in the jaws are extremely rare, with only 11 reported cases (2 cases in the maxilla and 9 cases in the mandible) in the literature. The infrequent occurrence of this entity presenting in this unusual location of the jaws often poses a diagnostic challenge to the oral pathologist, resulting in misdiagnosis. We present the 10th mandibular case of extracranial meningioma involving the right side of the mandible in a 56-year-old female patient. The clinical and radiographic presentation, histopathologic features, and histopathologic differential and immunohistochemical findings of this case are presented. The proposed pathogenesis, treatment options, and prognosis are also discussed along with a review of the literature.

Surgical Outcome of Trigeminal Schwannomas.

Simple SummaryTrigeminal schwannomas are the most common among non-vestibular schwannomas. Treatment of trigeminal schwannomas may be challenging due to critical anatomical relations and involvement of different aspects of the skull base. Advances in microsurgery have led to improved outcomes over the last decades, whereas in contrast, some advocate stereotactic radiotherapy as an effective therapy, controlling the tumor volume with few complications. In this manuscript, we present outcome and adverse events in a contemporary cohort of trigeminal schwannomas and discuss surgical advantages and disadvantages of different performed classic skull-base approaches. (1) Background: As resection of trigeminal schwannomas is challenging, due to anatomical involvement of the anterior, middle and posterior fossa, the appropriate approach is important. We report our experience with surgical resection of trigeminal schwannomas by simple and classic skull-base approaches. (2) Methods: We performed a retrospective single-center study including patients who underwent surgery for trigeminal schwannoma tumors between June 2007 and May 2020, concentrating on surgical technique, extent of resection, postoperative outcome and complications. (3) Results: We included 13 patients (median age 57.5 with range of 36-83 years, 53.8% (7/13) female. The most common preoperative clinical presentations were facial pain in six (46.2%), hypoacusis in four (30.8%), trigeminal nerve hypesthesia in 11 (V1 46.2% (6/13), V2 (61.5% (8/13), V3 46.2% (6/13)) and headache in three (23.1%) patients. In three cases, the tumor was resected in a two-stage technique. The intradural subtemporal approach was performed in six cases, the extradural technique in two cases, the retrosigmoid approach in five cases, a Kawase approach in two cases and the transnasal endoscopic approach in one case. The gross total resection rate was 76.9% (10/13) and the median follow-up time 24.0 (0–136) months. Three (23.1%) patients developed postoperative anesthesia in at least one branch of the trigeminal nerve. Trigeminal motor function was preserved in 11 (84.6%) patients. Ten of the 11 patients (76.9%) who reported decreased gustation, cerebellar ataxia, visual impairment, or headache improved postoperatively. Two (15.4%) patients exhibited minimal facial palsy (House and Brackmann II–III), which resolved during the follow-up. The total adverse event rate requiring surgical intervention during follow-up was 7.7%. Surgery-related mortality was 0%. (4) Conclusions: Trigeminal schwannomas are rare benign lesions with intra- and extracranial extension. Considering the low operative morbidity and satisfying functional outcome, gross total resection of trigeminal schwannomas is achievable by classic, but also individually tailored approaches. More invasive or combined techniques were not needed with meticulous surgical planning.

Four Lessons in Transcranial Lesions

Background Lesions involving the skull are rare and often discovered incidentally by imaging studies. Skull lesions are most commonly benign but may also be malignant. Typically, lesions of the skull are evaluated by computed tomography and/or magnetic resonance imaging. Imaging features can also suggest whether an identified lesion is benign or malignant. Definitive diagnosis of transcranial lesions ultimately requires biopsy and surgical resection. Cases Atypical meningioma: A 57-year-old woman with a history of hypertension and arthritis presented with a left frontal scalp mass. Imaging revealed a large left frontal transcranial heterogeneous mass with intracranial and extracranial extension. Malignant ossifying fibromyxoid tumor: A 26-year-old woman with history of hypothyroidism, polycystic ovarian syndrome, and sciatica presented with a left parietal scalp mass. Imaging demonstrated a large left homogenous parietal transcranial mass with intracranial and extracranial extension. Breast carcinoma metastasis: A 64-year-old woman with history of ER/PR/Her2-neu–negative, high-grade invasive ductal carcinoma status post mastectomy, lymph node dissection, and chemotherapy with early termination due to adverse effects presented with a left parietal scalp mass. Imaging demonstrated a large left parietal transcranial mass. Glioblastoma: A 52-year-old man with a history of glioblastoma status post resection x2, chemoradiation, and craniectomy, who was found to have a second recurrence. Imaging demonstrated tumor surrounding the resection cavity in the left parietal/temporal region with extension through the craniotomy defect into the scalp soft tissue.