Meningioma pathophysiology: Difference between revisions
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Brain invasion, 4 or more mitosis/10 HPF, [[necrosis]], increased cell count, high [[nucleus]]:[[cytoplasm]] ratio, increased [[nucleoli]] size, presence of sheeting | Brain invasion, 4 or more mitosis/10 HPF, [[necrosis]], increased cell count, high [[nucleus]]:[[cytoplasm]] ratio, increased [[nucleoli]] size, presence of sheeting | ||
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[[File:Grade 2 menigioma.jpg|thumb|none|300px|Grade 2 menigioma | [[File:Grade 2 menigioma.jpg|thumb|none|300px|Grade 2 menigioma]] | ||
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<gallery> | <gallery> | ||
Image:Meningeotheliomatous meningeoma 1.jpg| | Image:Meningeotheliomatous meningeoma 1.jpg|A smear showing meningothelial meningioma with syncytial appearance and whorl formation | ||
Image:Meningothelial Meningioma showing 2.jpg| | Image:Meningothelial Meningioma showing 2.jpg|A smear showing meningothelial meningioma with [[psammoma]] body | ||
Image:Meningothelioal Meningioma 3.jpg| | Image:Meningothelioal Meningioma 3.jpg|A smear showing meningothelial meningioma with onion bulb formation | ||
Image:Meningothelial Meningioma 4.jpg| | Image:Meningothelial Meningioma 4.jpg|A smear showing meningothelial meningioma [[HPS stain]] | ||
Image:Meningioma fibromatous variant.jpg| | Image:Meningioma fibromatous variant.jpg|A smear showing [[fibrous]] meningioma with [[spindle cell]]s in parallel bundles | ||
Image:Meningiom fibrous variant2.JPG| | Image:Meningiom fibrous variant2.JPG|A smear showing fibrous meingioma on EMA stain | ||
Image:Miningioma (2) transitional type.jpg| | Image:Miningioma (2) transitional type.jpg|A smear showing transitional meningioma with coexisting [[lobular]] and fasicular growth patterns | ||
Image:Psammomatous meningioma.jpg| | Image:Psammomatous meningioma.jpg|A smear showing psammomatous meningioma with numerous psammoma bodies | ||
Image:Angiomatous meningioma.jpg| | Image:Angiomatous meningioma.jpg|A smear showing angiomatous meningioma with hyalinized vessels | ||
Image:Microcystic meningeoma.jpg| | Image:Microcystic meningeoma.jpg|A smear showing microcystic meningioma with [[cystic]] appearance and increased [[pleomorphism]] of the elongated cells | ||
Image:Secretory meningioma.jpg| | Image:Secretory meningioma.jpg|A smear showing secretory meningioma with secretory [[granule]]s | ||
Image:Secretory meningioma PAS.jpg| | Image:Secretory meningioma PAS.jpg|A smear showing secretory meningioma with [[PAS stain]] positive secretory granules | ||
Image:Chordoid meningoma.jpg| | Image:Chordoid meningoma.jpg|A smear showing chordoid meningioma with myxoid appearance | ||
Image:Papillary meningioma.jpg| | Image:Papillary meningioma.jpg|A smear showing [[papillary]] meningioma with discohesive meningothelial [[tumor]] cells around a fibrovascular core | ||
Image:Rhabdoid meningioma.jpg| | Image:Rhabdoid meningioma.jpg|A smear showing rhabdoid meningiomao with abundant [[cytoplasm]] and cross-striations | ||
</gallery> | </gallery> | ||
Revision as of 20:15, 24 September 2015
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Meningioma Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Meningioma pathophysiology On the Web |
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American Roentgen Ray Society Images of Meningioma pathophysiology |
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Risk calculators and risk factors for Meningioma pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Haytham Allaham, M.D. [2]
Overview
Pathogenesis
Meningioma arise from arachnoidal cells, most of which are near the vicinity of the venous sinuses, and this is the site of greatest prevalence for meningioma formation. They are most frequently attached to the dura over the superior parasagittal surface of frontal and parietal lobes, along the sphenoid ridge, in the olfactory grooves, the sylvian region, superior cerebellum along the falx cerebri, cerebellopontine angle, and the spinal cord. The tumor is usually gray, well-circumscribed, and takes on the form of space it occupies. They are usually dome-shaped, with the base lying on the dura.
Meningiomas are the most common benign tumors of the brain (95% of benign tumors), rare meningioma can be malignant. It arises from the meninges which surround the brain and spinal cord. A small meningioma causes no significant signs. With the development of the lump, frequent symptoms include changes in vision, for example seeing double or blurriness, headache, hearing loss memory loss, etc. A meningioma doesn't always require immediate treatment. Treatments include surgery, radiation and a combination of them.
Histologically, the cells are relatively uniform, with a tendency to encircle one another, forming whorls and psammoma bodies (laminated calcific concretions). They have a tendency to calcify and are highly vascularized.
Genetics
Gross Pathology
Microscopic Pathology
- On microscopic histopathological analysis, whorled appearance, calcification, and psammoma bodies are characteristic findings of of meningioma.
- The table below differentiates between the three main groups of meningioma according to WHO histological classification:
| Grade | Histologic features | Image |
|---|---|---|
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Benign (Grade I) meningioma |
 | |
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Atypical (Grade II) meningioma |
Brain invasion, 4 or more mitosis/10 HPF, necrosis, increased cell count, high nucleus:cytoplasm ratio, increased nucleoli size, presence of sheeting |
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|
Anaplastic (Grade III) meningioma |
20 or more mitoses/10 HPF, histology similar to carcinoma or sarcoma |
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- Shown below is a series of microscopic images featuring specific findings seen in each subtype of meningioma:
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A smear showing meningothelial meningioma with syncytial appearance and whorl formation
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A smear showing meningothelial meningioma with psammoma body
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A smear showing meningothelial meningioma with onion bulb formation
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A smear showing meningothelial meningioma HPS stain
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A smear showing fibrous meningioma with spindle cells in parallel bundles
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A smear showing fibrous meingioma on EMA stain
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A smear showing transitional meningioma with coexisting lobular and fasicular growth patterns
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A smear showing psammomatous meningioma with numerous psammoma bodies
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A smear showing angiomatous meningioma with hyalinized vessels
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A smear showing microcystic meningioma with cystic appearance and increased pleomorphism of the elongated cells
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A smear showing secretory meningioma with secretory granules
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A smear showing secretory meningioma with PAS stain positive secretory granules
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A smear showing chordoid meningioma with myxoid appearance
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A smear showing rhabdoid meningiomao with abundant cytoplasm and cross-striations
_transitional_type.jpg)
