Difference between revisions of "Meningioma"

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*Thick-walled blood vessels, usually prominent.
*Thick-walled blood vessels, usually prominent.
*Calcification.
*Calcification.
Many subtypes exist:
*Atypical meningioma.
**Has invasion of the brain - WHO Grade 2.
*Angiomatous meningioma.
*Others.


Images:  
Images:  
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Notes:
Notes:
*May involute into benign sclerotic tissue.<ref>URL: [http://radiographics.rsna.org/content/23/3/785.long http://radiographics.rsna.org/content/23/3/785.long]. Accessed on: 3 November 2010.</ref>
*May involute into benign sclerotic tissue.<ref>URL: [http://radiographics.rsna.org/content/23/3/785.long http://radiographics.rsna.org/content/23/3/785.long]. Accessed on: 3 November 2010.</ref>
===Subtypes===
Many subtypes exist.<ref name=Ref_PSNP194>{{Ref PSNP|194}}</ref>
Grade I:
*Meningothelial.
**Most common.
**Microscopic: syncytial, nuclear clearing (pseudoinclusions).
*Fibrous (fibroblastic).
**Not collagen but looks like it. (It is really laminin or fibronectin).
*Transistional.
**Rare.
*Psammomatous.
**Microscopic: Psammoma bodies.
*Angiomatous (vascular).
**May bleed like stink.
*Microcystic.
**Microscopic: cystic appearance.
*Secretory.
**Microscopic: intracytoplasmic inclusions that are CEA +ve and PAS +ve.
**Assoc. with brain edema; may have a work outcome.
*Lymphoplasmacyte-rich.
*Metaplastic.
**Much talked about... but very rare.
**Microscopic: cartilage or bone formation.
Grade II:
*Invasive (invades the brain).
*Clear cell.
**Microscopic: clear cells - contain glycogen (PAS +ve).
**Epi.: usu. spinal cord.<ref>{{Ref PSNP|200}}</ref>
*Chordoid (chordoma-like).
**Microscopic: myxoid appearance.
Grade III:
*Papillary.
**Microscopic: true papillae.
*Rhaboid.
**Microscopic: rhadoid appearance (abundant cytoplasm


===Histomorphologic grading===
===Histomorphologic grading===

Revision as of 23:43, 8 November 2010

Meningioma a very common tumour in neuropathology.

General

Prevalence

  • Common.

Radiology

  • Extra-axial.

Prognosis

  • Most are benign.
    • May be malignant.

Genetics

Microscopic

Features (memory device WTC):

  • Whorled appearance - key feature.
  • Thick-walled blood vessels, usually prominent.
  • Calcification.

Images:

Notes:

  • May involute into benign sclerotic tissue.[2]

Subtypes

Many subtypes exist.[3]

Grade I:

  • Meningothelial.
    • Most common.
    • Microscopic: syncytial, nuclear clearing (pseudoinclusions).
  • Fibrous (fibroblastic).
    • Not collagen but looks like it. (It is really laminin or fibronectin).
  • Transistional.
    • Rare.
  • Psammomatous.
    • Microscopic: Psammoma bodies.
  • Angiomatous (vascular).
    • May bleed like stink.
  • Microcystic.
    • Microscopic: cystic appearance.
  • Secretory.
    • Microscopic: intracytoplasmic inclusions that are CEA +ve and PAS +ve.
    • Assoc. with brain edema; may have a work outcome.
  • Lymphoplasmacyte-rich.
  • Metaplastic.
    • Much talked about... but very rare.
    • Microscopic: cartilage or bone formation.

Grade II:

  • Invasive (invades the brain).
  • Clear cell.
    • Microscopic: clear cells - contain glycogen (PAS +ve).
    • Epi.: usu. spinal cord.[4]
  • Chordoid (chordoma-like).
    • Microscopic: myxoid appearance.

Grade III:

  • Papillary.
    • Microscopic: true papillae.
  • Rhaboid.
    • Microscopic: rhadoid appearance (abundant cytoplasm

Histomorphologic grading

Grading:[3]

  • Grade 1:
    • Low mitotic rate.
    • Excludes clear cell, chordoid, papillary, and rhabdoid subtypes.
  • Grade 2 (either #1 or #2):
    1. Brain-invasive meningioma.
      • Protrusion of meningioma into brain.
        • Meninogioma with entraped GFAP +ve tissue.
    2. Atypical meningioma (by histomorphology).
      • Intermediate mitotic rate (>= 4 mitoses/10 HPF - for whatever HPF means, see HPFitis.)
      • Three of the following five features:
        1. Sheeting architecture.
        2. High NC ratio clusters; clusters of "lymphocyte-like" cells.
        3. Hypercellularity.
        4. Macronucleoli.
        5. Necrosis not caused by treatment, e.g. radiation or embolization.
  • Grade 3 (either of the following):
    • High mitotic rate (>=20 mitoses/10 HPF - for whatever HPF means, see HPFitis.)
    • "Frank anaplasia"; marked nuclear atypia.

Notes:

  • Grade II soft criteria memory device HMNs: hypercellular, macronucleoli, NC ratio increased, necrosis, sheeting.

IHC

  • EMA +ve.[5]
    • Other CKs usu. -ve.

See also

References

  1. URL: http://moon.ouhsc.edu/kfung/jty1/neurotest/Q13-Ans.htm. Accessed on: 26 October 2010.
  2. URL: http://radiographics.rsna.org/content/23/3/785.long. Accessed on: 3 November 2010.
  3. 3.0 3.1 Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 194. ISBN 978-0443069826.
  4. Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 200. ISBN 978-0443069826.
  5. Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 13. ISBN 978-0443069826.