Meningioma

Definition

Meningiomas are tumors that originate in the meninges, the membranes that surround the brain and spinal cord.

Epidemiology

The worldwide incidence of primary brain tumors in 2015 was estimated to be 10.82 per 100,000 people per year. Meningioma is more common in adults than in children with an incidence of 37.75 per 100,000 in the 75 to 84 age group. Whereas 0.14 per 100,000 in children from 0 to 19 years of age.

Cause and riskfactors

• Most meningiomas are sporadic in origin, but some have been associated with certain conditions and risk factors.[1].
• Environmental factors such as obesity, alcoholism, exposure to ionizing radiation, radiotherapy, hormonal factors such as exposure to exogenous hormones, hormonal replacement therapy, use of oral contraceptive pills, and breast cancer can increase the risk of incidence of meningiomas.

Types

• These tumors are classified into three grades, according to the World Health Organization (WHO).[2].
• The majority of meningiomas are benign and considered grade 1.
• About 1 to 3% of meningiomas can be transformed into malignant tumors with a 5-year survival rate of 32 to 64%.
• Most meningiomas are not cancerous (benign), though a minority of meningiomas can be classified as atypical or cancerous (malignant).
• Though rare, malignant meningiomas can be highly aggressive.
• However, even benign meningiomas can cause problems if their growth affects neighboring areas of the brain.
• Though most meningiomas grow slowly, there is no way to predict the rate of growth for a particular meningioma or to know how long a specific meningioma was growing before it was diagnosed.

Signs and symptoms

• Signs and symptoms can vary but may include seizures, headaches, weakness in the arms and legs, and vision loss.
• Sometimes memory loss, carelessness, and unsteadiness are the only symptoms.

Clinical presentation

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed.

80%-99% of people have these symptoms

• Chromosomal breakage induced by ionizing radiation
• Increased sensitivity to ionizing radiation
• Intracranial meningioma

30%-79% of people have these symptoms

• Abnormal brain FDG positron emission tomography
• Amenorrhea(Abnormal absence of menstruation)
• Bitemporal hemianopia
• Decreased circulating ACTH level
• Decreased circulating cortisol level(Low blood cortisol level)
• Decreased circulating follicle stimulating hormone level
• Decreased circulating luteinizing hormone level
• Decreased serum estradiol
• Decreased serum testosterone level(Decreased serum testosterone levels)
• Focal T2 hypointense thalamic lesion
• Focal-onset seizure(Seizure affecting one half of brain)
• Headache(Headaches)
• Hypogonadotropic hypogonadism
• Impotence(Difficulty getting a full erection)
• Increased circulating prolactin concentration
• Nausea and vomiting
• Pituitary hypothyroidism(Low thyroid gland function due to abnormal pituitary gland)
• Secondary growth hormone deficiency

5%-29% of people have these symptoms

• Abnormal central sensory function
• Abnormal cerebellum morphology(Abnormality of the cerebellum)
• Abnormal kinetic perimetry test
• Abnormality of the sense of smell(Abnormal sense of smell)
• Ataxia
• Difficulty walking(Difficulty in walking)
• Enlarged pituitary gland
• Facial palsy(Bell's palsy)
• Hemiparesis(Weakness of one side of body)
• Hydrocephalus(Too much cerebrospinal fluid in the brain)
• Hypothalamic hypothyroidism
• Increased intracranial pressure(Rise in pressure inside skull)
• Lower limb muscle weakness(Lower extremity weakness)
• Neoplasm of the anterior pituitary
• Neurofibromas
• Obesity(Having too much body fat)
• Oculomotor nerve palsy
• Ophthalmoplegia(Eye muscle paralysis)
• Papilledema
• Reduced circulating prolactin concentration
• Slow decrease in visual acuity(Slow decrease in sharpness of vision)
• Spinal meningioma
• Trigeminal neuralgia
• Upper limb muscle weakness(Decreased arm strength)
• Visual acuity test abnormality
• Weak extraocular muscles

Diagnosis

Brain magnetic resonance imaging (MRI) is the gold standard radiological investigation for diagnosing meningioma.[3].

Treatment

• The treatment varies depending on the location of the meningioma and the symptoms caused by the tumor.
• Careful observation is sometimes the best course of action for people with a meningioma.
• When treatment is necessary, surgery and radiation are the most common forms of treatment.
• Radiation may be used if the meningioma cannot be operated on or if the meningioma is only partially removed by surgery.
• Radiation may also be used in cases of malignant, atypical, or recurrent tumors.
• Other treatments that have been tried or are being explored include hydroxyurea, epidermal growth factor receptor inhibitors, platelet-derived growth factor receptor inhibitors, vascular endothelial growth factor inhibitors, immunotherapy to stimulate the immune system, and somatostatin analogs which prevent the release of growth hormones.

Prognosis

The 5-year progression-free survival for grade 1 is 95.7%, for grade 2 is 81.8%, and for grade 3 is 46.7%, while the 10-year progression-free survival for grade 1 is 90.4.7%, for grade 2 is 69.4%.

NIH genetic and rare disease info

• NIH info on Meningioma

Meningioma is a rare disease.

Meningioma Resources
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