Difference between revisions of "Meningioma"

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(→‎Grade I: subdivide)
(→‎Grade II: +images)
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====Grade II====
====Grade II====
*Invasive (invades the brain).
=====Invasive=====
*Clear cell.
*Invades the brain.
**Microscopic: clear cells - contain glycogen (PAS +ve).
 
**Epi.: usu. spinal cord.<ref>{{Ref PSNP|200}}</ref>
Images:
*Chordoid (chordoma-like).
*[http://moon.ouhsc.edu/kfung/jty1/Composites/FNA0IE18-Meningioma-Invasion.htm Meningioma with brain invasion (ouhsc.edu)].
**Microscopic: myxoid appearance.
 
=====Clear cell=====
Epidemiology:
*Usu. spinal cord.<ref>{{Ref PSNP|200}}</ref>
 
Microscopic:
*Clear cells - contain glycogen (PAS +ve).
 
=====Chordoid=====
*Chordoma-like.
 
Microscopic:
*Myxoid appearance.
 
Image:
*[http://frontalcortex.com/?page=oll&topic=24&qid=914 Chordoid meningioma (frontalcortex.com)].


====Grade III====
====Grade III====

Revision as of 14:39, 12 October 2011

Meningioma a very common tumour in neuropathology.

General

Prevalence

  • Common.
  • May be caused by prior radiation.

Radiology

  • Extra-axial.

Prognosis

  • Most are benign.
    • May be malignant.

Genetics

Microscopic

Features (memory device WCN):

  • Whorled appearance - key feature.
  • Calcification, psammomatous (target-like appearance; (tight) onion skin).
  • +/-Nuclear pseudoinclusions - focal nuclear clearing with a sharp interface to unremarkable chromatin.

Images:

Notes:

  • May involute into benign sclerotic tissue.[2]
  • Thick-walled blood vessels = feature of schwannoma.

Morphologic subtypes

  • Many subtypes exist.[3]
  • The histologic subtypes generally don't have much prognostic significance.
    • Some subtypes are high grade by definition; also see histologic grading.

Grade I

Meningothelial
  • Most common.

Microscopic:

Fibrous
  • AKA fibroblastic.
  • Not collagen but looks like it. (It is really laminin or fibronectin).
Transistional
  • Rare.
Psammomatous

Microscopic:

Angiomatous
  • AKA vascular.
  • May bleed like stink.
Microcystic

Microscopic:

  • Cystic appearance.
Secretory
  • Assoc. with brain edema; may have a worse outcome.

Microscopic:[4]

  • Eosinophilic intracytoplasmic inclusions that are CEA +ve and PAS +ve.

DDx:

  • Metastatic mucinous adenocarcinoma.
Lymphoplasmacyte-rich

Microscopic:

  • Lymphocytes.
  • Plasma cells.
Metaplastic
  • Much talked about... but very rare.

Microscopic:

  • Cartilage or bone formation.

Grade II

Invasive
  • Invades the brain.

Images:

Clear cell

Epidemiology:

  • Usu. spinal cord.[5]

Microscopic:

  • Clear cells - contain glycogen (PAS +ve).
Chordoid
  • Chordoma-like.

Microscopic:

  • Myxoid appearance.

Image:

Grade III

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

Histologic grading

Grading:[3]

  • Grade 1:
    • Low mitotic rate (< 4 mitoses/10 HPF - for whatever HPF means, see HPFitis).
    • Excludes clear cell, chordoid, papillary, and rhabdoid subtypes.
  • Grade 2 (either #1, #2 or #3):
    1. Brain-invasive meningioma.
      • Protrusion of meningioma into brain.
        • Meninogioma with entraped GFAP +ve tissue.
    2. Atypical meningioma (by histomorphology) - either A or B.
      • A. Intermediate mitotic rate (>= 4 mitoses/10 HPF - for whatever HPF means, see HPFitis.)
      • B. 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.
    3. Clear cell or chordoid subtype.
  • Grade 3 (either of the following):
    • High mitotic rate (>=20 mitoses/10 HPF - for whatever HPF means, see HPFitis.)
    • "Frank anaplasia"; marked nuclear atypia.
    • Papillary or rhabdoid subtype.

Notes:

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

IHC

  • EMA +ve.[6]
  • Other CKs usually -ve.

DDx of meningioma & IHC[7]

  • S-100 +ve - schwannoma.
    • +ve in ~80% of fibrous meningiomas.
  • CD34 +ve - solitary fibrous tumour.
    • +ve in ~60% of fibrous meningiomas.
  • EMA +ve in ~30% of hemangiopericytoma.
  • Claudin-1 - new kid on the block: +ve in meningioma, but low sensitivity.

Standard work-up (UHN)[8]

  • Ki-67 >5-10% - predicts re-occurrence.
  • PR (progesterone receptor) +ve in 2/3; -ve PR predicts re-occurrence.

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. URL: http://moon.ouhsc.edu/kfung/jty1/Com04/Com405-1-Diss.htm. Accessed on: 12 October 2011.
  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. 200. ISBN 978-0443069826.
  6. 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.
  7. Hahn HP, Bundock EA, Hornick JL (February 2006). "Immunohistochemical staining for claudin-1 can help distinguish meningiomas from histologic mimics". Am. J. Clin. Pathol. 125 (2): 203–8. doi:10.1309/G659-FVVB-MG7U-4RPQ. PMID 16393681. http://ajcp.ascpjournals.org/content/125/2/203.full.pdf.
  8. Croul, SE. 8 November 2010.

External links