Background

• Meningiomas are tumors that grow on or around the dura mater and are thought to develop from meningothelial cells (arachnoid cap cells). Although meningiomas may develop everywhere the meninges are present, they often appear in the parasagittal area, cerebral convexities, skull base, and falx. The prevalence of meningiomas among primary brain tumors is between 34.4% and 36.4%. The percentage of meningiomas among orbital tumors is just 4%. Sphenoid wing meningiomas are one of the most common skull base meningiomas. They can extend into neighboring structures such as the orbit (eye socket), cavernous sinus, and temporal bone. Sphenoid wing meningiomas account for around 15-25% of all meningiomas, making them the most common supratentorial lesion. 
• Meningiomas were first reported in 1614 after an autopsy performed by Felix Plater. The name “meningioma” was initially used to characterize these lesions in 1938 by Cushing and Eisenhardt, who identified it as a distinct group of intraparenchymal tumors.  
• Sphenoid wing meningiomas can have different growth patterns. They can either form a nodular mass, meningioma en masse or exhibit a flat and carpet-like growth pattern, known as meningioma en plaque. The en masse pattern appears as a distinct tumor mass, while the en plaque pattern spreads along the affected area, resembling a flat sheet. 

Epidemiology

• Prevalence: Meningiomas are the most common primary brain tumors, accounting for approximately 13-20% of all brain tumors and 34-36.4%. Among meningiomas, sphenoid wing meningiomas represent a notable subset, comprising about 15-20% of all meningiomas. 
• Gender and Age Distribution: Meningiomas on the wings of sphenoids are slightly more common in women than men, with about a 2:1 ratio of women to men. Most of the time, these tumors happen in adults, and most happen between the ages of 50 and 70. But they can also affect people of all ages, including young and older. 
• Risk Factors: Uncertainty exists about the precise etiology of sphenoid wing meningiomas. However, several risk factors have been found, such as previous radiation exposure, neurofibromatosis type 2 (NF2) genetic condition, and the female gender. 
• Association with Genetic Disorders: Sphenoid wing meningiomas are often associated with neurofibromatosis type 2 (NF2), an inherited condition characterized by the development of tumors in the nervous system. Meningiomas of many varieties, including sphenoid wing meningiomas, are more likely to develop in people with NF2, brought on by mutations in the NF2 gene. 
• Ethnic and Geographic Variations: Sphenoid wing meningiomas do not appear to have significant ethnic or geographic variations in their occurrence. They have been reported worldwide in various populations. 

Anatomy

Pathophysiology

• Origin and Cell of Origin: Arachnoid cap cells, or meningothelial cells, line the meninges and are thought to be the origin of sphenoid wing meningiomas. These cells might potentially develop into tumours if they proliferate abnormally. 
• Genetic Alterations: The exact genetic alterations responsible for the development of sphenoid wing meningiomas are not fully understood. However, studies have identified several genetic abnormalities commonly associated with meningiomas in general. For example, mutations in the NF2 gene, a tumor suppressor gene, are frequently found in meningiomas, including sphenoid wing meningiomas. These mutations lead to the loss of function of the NF2 protein and contribute to the uncontrolled growth of meningioma cells. 
• Tumor Growth and Invasion: Sphenoid wing meningiomas typically grow slowly and tend to invade nearby structures. These tumors can extend into the adjacent bone, such as the sphenoid wing, temporal bone, or orbit. They can also invade the cavernous sinus, a complex venous structure located at the base of the skull. The invasive nature of sphenoid wing meningiomas can make complete surgical removal challenging. 
• Compression and Mass Effect: As sphenoid wing meningiomas grow, they can exert pressure on surrounding brain tissue and structures, leading to compression and mass effect. This can result in various neurological symptoms depending on the tumor’s location. Common symptoms include headaches, visual disturbances, seizures,numbness in the face or limbs, and cognitive changes. 
• Blood Supply: Sphenoid wing meningiomas receive their blood supply from the surrounding blood vessels, primarily branches of the external and internal carotid arteries. The tumor blood vessels can become abnormal and exhibit characteristics such as increased vascularity or irregular structure. 

Etiology

• Genetic Factors: Sphenoid wing meningiomas may have a hereditary component. Meningiomas, notably those in the sphenoid wing, are tumours of the meninges that have been linked to mutations in certain genes. For example, neurofibromatosis type 2 (NF2) gene mutations are commonly found in meningiomas, particularly those associated with the sphenoid wing. NF2 gene mutations can lead to the loss of function of the NF2 protein, which usually acts as a tumor suppressor, regulating cell growth and division. 
• Radiation Exposure: Previous exposure to ionizing radiation, such as radiation therapy for other conditions, has been identified as a risk factor for developing meningiomas, including sphenoid wing meningiomas. The radiation may induce genetic alterations and cellular damage, contributing to the formation of tumors over time. 
• Hormonal Factors: Estrogen and progesterone receptors are frequently expressed in meningiomas, suggesting a potential role of hormonal factors in their development. It has been observed that sphenoid wing meningiomas occur more frequently in women, especially those of childbearing age. Hormonal fluctuations during pregnancy and menopause may influence the growth and progression of these tumors. 
• Prior Head Trauma: Some evidence suggests that a history of head trauma or skull fractures may increase the risk of developing sphenoid wing meningiomas. However, the exact mechanisms linking head trauma to tumor formation are poorly understood. 
• Other Factors: Other potential factors that have been suggested to contribute to developing sphenoid wing meningiomas include certain chemicals or environmental exposures, viral infections, and underlying medical conditions, although the evidence supporting these associations is limited. 

Genetics

Prognostic Factors

• Tumor Grade: Meningiomas are classified into different grades based on histopathological characteristics. Grade I is the most common and benign, and Grades II and III are more aggressive and potentially malignant. Higher tumor grades are associated with a poorer prognosis, as high-grade meningiomas tend to grow more rapidly, invade nearby structures, and have a higher likelihood of recurrence after treatment. 
• Tumor Size: The size of the sphenoid wing meningioma at the time of diagnosis can impact the prognosis. Larger tumors may be associated with a more significant mass effect, compression of surrounding structures, and increased surgical difficulty. They have a higher chance of regrowth or recurrence following treatment. 
• Invasion and Adjacent Structure Involvement: The extent of invasion and involvement of adjacent structures, such as the skull base, orbit, cavernous sinus, and temporal bone, can influence the prognosis of sphenoid wing meningiomas. Extensive invasion into critical structures may limit the feasibility of complete surgical resection and increase the risk of complications and tumor recurrence. 
• Tumor Location: The specific location of the sphenoid wing meningioma within the skull base can impact prognosis. For example, tumors in the medial (clinoidal) region of the sphenoid wing may be more challenging to remove entirely due to their proximity to vital structures such as the internal carotid artery. Tumors that involve the optic canal or optic nerve may also have implications for vision and overall prognosis. 
• Patient Age and Health Status: Patient-related factors, such as age and overall health status, can influence the prognosis of sphenoid wing meningiomas. Generally, younger patients with good overall health tend to have better outcomes than older patients or those with underlying medical conditions that may complicate treatment and recovery. 
• Genetic Factors: In some cases, specific genetic alterations, such as mutations in the NF2 gene, can impact the prognosis of sphenoid wing meningiomas. Genetic testing and counseling may sometimes be recommended to provide additional prognostic information and guide treatment decisions. 

Clinical History

The typical clinical presentation of sphenoid wing meningiomas, considering age group, associated comorbidity or activity, and the acuity of presentation: 

• Age Group: Sphenoid wing meningiomas can affect individuals of all ages, but they are most diagnosed in adults, particularly in the fifth to seventh decades of life.  

Physical Examination

• Visual Assessment: The healthcare provider may evaluate visual acuity and visual fields and perform a fundoscopic examination to assess the optic nerve and retina. This is important as sphenoid wing meningiomas can compress or invade the optic nerve or canal, leading to visual disturbances or changes. 
• Neurological Examination: A thorough neurological examination assesses the patient’s cranial nerves, motor function, sensation, coordination, and reflexes. Specific attention may be given to cranial nerves II (optic), III (oculomotor), IV (trochlear), and VI (abducens), as they can be affected by sphenoid wing meningiomas. 
• Eye Movements and Pupillary Response: The healthcare provider may evaluate eye movements, looking for limitations or abnormalities. Additionally, they may assess the size and reactivity of the pupils to light. 
• Proptosis and Orbital Examination: If the sphenoid wing meningioma extends into the orbit, the provider may inspect and measure the degree of proptosis (forward displacement of the eyeball) using an exophthalmometer. They may also assess extraocular muscle function and palpate for any orbital masses or abnormalities. 
• Facial Sensation and Motor Function: The healthcare provider may test the patient’s facial sensation, assessing for numbness or sensory deficits in different face areas. They may also assess facial muscle strength and symmetry. 
• Head and Neck Examination: A general head and neck exam may be performed by the healthcare professional to look for any masses that are visible or palpable, as well as any asymmetry or other abnormalities in the areas of the skull, face, or neck. 

Age group

Associated comorbidity

• Sphenoid wing meningiomas can occur in individuals without specific comorbidities or associated activities. However, certain conditions or factors may be associated with an increased risk of developing meningiomas in general.
• For example, individuals with neurofibromatosis type 2 (NF2), a genetic disorder, have an increased risk of developing meningiomas, including sphenoid wing meningiomas. Additionally, previous radiation therapy to the head or skull may increase the risk of developing these tumors. 

Associated activity

Acuity of presentation

• The acuity of presentation of sphenoid wing meningiomas can vary. Sometimes, the tumor may grow slowly over time, leading to a more indolent presentation.
• On the other hand, rapid tumor growth or complications such as bleeding within the tumor can lead to a more acute presentation. 

Differential Diagnoses

• Meningeal Metastases: Metastatic tumors from other primary cancers can involve the meninges, including the sphenoid wing region. Imaging studies and thoroughly evaluating the patient’s medical history are essential in distinguishing between primary meningiomas and metastatic lesions. 
• Skull Base Tumors: Other tumors originating from the skull base structures can mimic sphenoid wing meningiomas. Examples include chordomas, chondrosarcomas, and fibrous dysplasia. Careful imaging evaluation and consideration of clinical features can help differentiate between these entities. 
• Pituitary Adenoma: Pituitary adenomas can cause mass effects and compress adjacent structures, including the optic nerves and chiasm. They can sometimes extend into the sphenoid wing region. Clinical and endocrine evaluation and imaging can aid in distinguishing pituitary adenomas from sphenoid wing meningiomas. 
• Optic Nerve Glioma: Optic nerve gliomas, particularly those involving the anterior visual pathway, can present with visual disturbances and optic nerve compression. They can occasionally extend into the sphenoid wing region. Imaging studies, including MRI, help differentiate between optic nerve gliomas and sphenoid wing meningiomas. 
• Other Meningioma Subtypes: While sphenoid wing meningiomas are a specific subtype, other meningioma subtypes can also involve the sphenoid wing region. For example, olfactory groove meningiomas or tuberculum sellae meningiomas can extend laterally into the sphenoid wing. Detailed imaging evaluation and clinical correlation are necessary for accurate diagnosis and differentiation. 
• Inflammatory Lesions: Inflammatory conditions, such as pseudotumor cerebri (idiopathic intracranial hypertension) or orbital inflammatory disease, can present similar symptoms and imaging findings, including optic nerve sheath thickening or enlargement. Clinical evaluation, imaging, and sometimes additional laboratory tests can help differentiate between these conditions and sphenoid wing meningiomas. 
• Vascular Lesions: Certain vascular abnormalities, such as dural arteriovenous fistulas or cavernous sinus thrombosis, can mimic the imaging appearance of sphenoid wing meningiomas. Vascular imaging studies, such as angiography or magnetic resonance angiography (MRA), may be necessary to exclude these diagnoses. 

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

• Observation: In cases where the meningioma is small, asymptomatic, and not causing significant compression or neurological deficits, a conservative observation approach with regular imaging follow-up may be chosen. This approach is mainly considered for elderly patients or those with multiple comorbidities that make surgical intervention risky. 
• Symptom management: Addressing specific symptoms such as headaches, seizures, or visual disturbances through appropriate medications or supportive measures can improve the patient’s quality of life. 

• Medications: Pharmaceutical agents may be used to manage symptoms associated with sphenoid wing meningiomas. For example, analgesics for headache management, antiepileptic drugs for seizure control, or corticosteroids to reduce peritumoral edema and associated symptoms. 

• Surgery: Surgical resection is often the primary treatment modality for sphenoid wing meningiomas. The goal is to achieve maximal safe resection while preserving neurological function. The surgical approach depends on tumor size, location, and extension. Different techniques may be utilized, such as craniotomy, skull base surgery, or endoscopic approaches. 
• Radiation Therapy: Radiation therapy may be recommended in cases where complete resection cannot be achieved or in recurrent or residual tumors. External beam radiation therapy, including stereotactic radiosurgery, can target the tumor, reduce its size, or control further growth. 
• Embolization: In select cases, embolization may be performed before surgery to reduce vascularity and facilitate safer surgical resection. 

• Preoperative Phase: This phase involves thorough preoperative evaluation, including clinical assessment, imaging studies (MRI, CT scan), and potentially additional tests to assess the tumor’s characteristics and plan the surgical approach. 
• Intraoperative Phase: The surgical phase includes the tumor resection, during which the surgeon aims to achieve maximal safe resection while preserving vital structures and minimizing neurological deficits. 
• Postoperative Phase: After surgery, close postoperative monitoring is essential. This includes neurological assessment, management of pain and discomfort, monitoring for potential complications, and initiating appropriate rehabilitation measures if needed. 
• Long-term Follow-up: Regular follow-up evaluations, including imaging studies and clinical assessments, are necessary to monitor tumor recurrence or progression and manage potential long-term effects or complications. 

Medication

Future Trends

Media Gallary

References

• Meningioma:ncbi.nih.gov