"Meningiomas are best imaged with contrast-enhanced MRI, as this most accurately delineates the tumour, the presence of intra- and trans-osseous extension, and its relationship to the underlying brain. CT, however, is useful if bony anatomy is required (e.g. at the base of the skull), when patients cannot have an MRI, and especially when the meningioma is entirely ossified/calcified (see burnt-out meningioma)."
"The 2023 NCCN guidelines for surgically treated Grade 1 and 2 meningiomas recommend a follow-up brain MRI at 3, 6, and 12 months, then every 6–12 months for 5 years, and subsequently every 1–3 years. For WHO Grade 3 meningiomas, recommendations include a brain MRI every 2-4 months for the first 3 years, followed by every 3–6 months thereafter 36."
"The 2023 NCCN guidelines for surgically treated Grade 1 and 2 meningiomas recommend a follow-up brain MRI at 3, 6, and 12 months, then every 6–12 months for 5 years, and subsequently every 1–3 years. For WHO Grade 3 meningiomas, recommendations include a brain MRI every 2-4 months for the first 3 years, followed by every 3–6 months thereafter 36."
"The 2023 NCCN guidelines for surgically treated Grade 1 and 2 meningiomas recommend a follow-up brain MRI at 3, 6, and 12 months, then every 6–12 months for 5 years, and subsequently every 1–3 years. For WHO Grade 3 meningiomas, recommendations include a brain MRI every 2-4 months for the first 3 years, followed by every 3–6 months thereafter 36."
"A broad division of meningiomas into primary intradural (which may or may not have a secondary extradural extension) and primary extradural is also used, although the latter is rare, accounting for only 1-2% of cases 25. Ectopic primary meningiomas include tumours residing in the head and neck, orbit, nose, paranasal sinuses, oropharynx, and even more remote sites (e.g. lung)."
"TERT promoter mutation"
"TERT promoter mutation: grade 3"
"The 2023 NCCN guidelines for surgically treated Grade 1 and 2 meningiomas recommend a follow-up brain MRI at 3, 6, and 12 months, then every 6–12 months for 5 years, and subsequently every 1–3 years. For WHO Grade 3 meningiomas, recommendations include a brain MRI every 2-4 months for the first 3 years, followed by every 3–6 months thereafter 36."
"MR spectroscopy: usually does not play a significant role in diagnosis, but can help distinguish meningiomas from mimics. Features include:"
"MR perfusion: good correlation between volume transfer constant (k-trans) and histological grade 26"
Expected headings
"Subtypes"
"Grading"
"Grade 2 criteria"
"Grade 3 criteria"
"Brain invasion"
"Macroscopic features"
"Molecular markers"
"Signal characteristics"
"Helpful imaging signs"
"Oedema"
"Most commonly, they are either classified according to the histological subtype (e.g. rhabdoid or papillary, etc.), location (e.g. skull base, spinal, intraosseous, intraventricular, etc.), or by aetiology (e.g. radiation-induced, etc.)."
"Otherwise, meningiomas are graded from grade 1 to 3 based on histological features (e.g. mitotic index), some histological subtypes (e.g. chordoid and clear cell meningiomas), and molecular features (see below) 7,11,21,31."
"More than half of the meningiomas demonstrate a variable amount of vasogenic oedema in adjacent brain parenchyma 22. Correlations between age, gender, tumour size, rapid growth, location (convexity and parasagittal > elsewhere), histologic type, and invasion in malignant meningiomas have been suggested in the literature but not yet confirmed. Although in general, the presence of severe adjacent oedema is considered more compatible with aggressive meningiomas, in some histologically benign types such as secretory type, oedema can be disproportionately larger than the small tumour size."
"Most commonly, they are either classified according to the histological subtype (e.g. rhabdoid or papillary, etc.), location (e.g. skull base, spinal, intraosseous, intraventricular, etc.), or by aetiology (e.g. radiation-induced, etc.)."
"A broad division of meningiomas into primary intradural (which may or may not have a secondary extradural extension) and primary extradural is also used, although the latter is rare, accounting for only 1-2% of cases 25. Ectopic primary meningiomas include tumours residing in the head and neck, orbit, nose, paranasal sinuses, oropharynx, and even more remote sites (e.g. lung)."
"Occasionally, transosseous, or intraosseous involvement with prominent hyperostosis may result in local mass effect (e.g. proptosis)."
"Meningiomas are best imaged with contrast-enhanced MRI, as this most accurately delineates the tumour, the presence of intra- and trans-osseous extension, and its relationship to the underlying brain. CT, however, is useful if bony anatomy is required (e.g. at the base of the skull), when patients cannot have an MRI, and especially when the meningioma is entirely ossified/calcified (see burnt-out meningioma)."
"dural metastases (e.g. breast cancer)"
"sclerotic metastases (e.g. prostate and breast carcinoma)"
"CSF cleft sign, which is not specific for meningioma, but helps establish the mass to be extra-axial; loss of this can be seen in grade II and grade III, which may suggest brain parenchyma invasion"
"useful sign in parasellar tumours, in distinguishing a meningioma from a pituitary macroadenoma; the latter typically does not narrow vessels"
"Meningiomas can have a dual blood supply. The majority of tumours are predominantly supplied by meningeal vessels; these are responsible for the sunburst or spoke-wheel pattern observed on MRI/DSA. Some tumours also have a significant pial supply to the periphery of a tumour."