Oligodendroglioma

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Oligodendroglioma is CNS tumour that is typically in the cerebral hemispheres.

Oligodendroglioma
Diagnosis in short

Oligodendroglioma. H&E stain.
LM highly cellular lesion composed of cells resembling fried eggs (oligodendrocytes) with a round nucleus (important), distinct cell borders, +/-clear cytoplasm - useful feature (if present), acutely branched capillary sized vessels ("chicken-wire" like appearance), calcifications
LM DDx neurocytoma, clear cell variant of ependymoma, seminoma / dysgerminoma / germinoma
Molecular +/-loss of 1p and 19q (common)
Site neuropathology tumours - cerebral hemispheres, posterior fossa (rare), spinal cord (very rare)
Radiology intra-axial mass, +/-calcifications (best seen on CT), nonenhancing or enhancing
Prognosis moderate - dependent on grade

General

  • Do not arise from oligodendrocytes.
    • Arise from glial precursor cells.

Prognosis by flavours (average survival):[1]

  • WHO grade II: 10-15 years.
  • WHO grade III: 3-5 years.

Gross/radiologic

Location:

  • Cerebral hemispheres - most often frontal lobe, followed by parietal and temporal lobes.[2]
  • Posterior fossa (rare).
  • Intramedullary spinal cord (very rare).

Radiologic features:[2]

  • Intra-axial mass.
  • +/-Calcifications (best seen on CT).
  • Nonenhancing or enhancing.
  • Occasionally well-circumscribed.

Microscopic

Features:

  • Highly cellular lesion composed of:
    • Cells resembling fried eggs (oligodendrocytes) with:
      • Round nucleus - key feature.
      • Distinct cell borders.
      • Moderate-to-marked nuclear atypia.
      • Clear cytoplasm - useful feature (if present).
        • Some oligodendrogliomas have eosinophilic cytoplasm with focal perinuclear clearing.
    • Acutely branched capillary sized vessels - "chicken-wire" like appearance.
      • Abundant, delicate appearing; may vaguely resemble a paraganglioma at low power.
  • Calcifications - important feature.[3]

Note:

  • Tumour cells may be plasmacytoid, i.e. have a plasma cell-like appearance.[4]

DDx:

  • Neurocytoma also have perinuclear clearing and well-defined cellular borders.
    • Pineocytomatous/neurocytic rosettes = (irregular) rosette with a large meshwork of fibers (neuropil) at the centre.

Notes:

Images

  • Oligodendroglioma high mag. (WC)

  • Oligodendroglioma low mag. (WC)

www:

Histologic grading

Come in two flavours:

  1. WHO grade II.
    • This is most oligodendrogliomas.
  2. WHO grade III.
    • Features for calling high grade:[1]
      • Endothelial hypertrophy.
        • Plump/large endothelial cells.
      • Necrosis.
      • High mitotic rate (6 mitoses/10 HPF for whatever "HPF" means, see HPFitis).

IHC

Features:

  • MAP-2 +ve.[5]
  • GFAP +ve (variable).
    • Some subtypes +ve - should not be used to distinguish.[6]
  • EMA +ve.
  • IDH-1 -ve.
    • 18% +ve in one series of children,[7] 23% +ve in another series.[8]
  • p53 -ve.
    • Useful for differentiating astrocytoma vs. oligodendroglioma.
  • Ki-67.

Molecular pathology

Losses of 1p and 19q both helps with diagnosis and is prognostic:[9]

  • Greater chemosensitivity
  • Better prognosis.

See also

References

  1. ↑ 1.0 1.1 Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 98. ISBN 978-0443069826.
  2. ↑ 2.0 2.1 Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 94. ISBN 978-0443069826.
  3. ↑ URL: http://www.emedicine.com/radio/topic481.htm.
  4. ↑ Aldape, K.; Burger, PC.; Perry, A. (Feb 2007). "Clinicopathologic aspects of 1p/19q loss and the diagnosis of oligodendroglioma.". Arch Pathol Lab Med 131 (2): 242-51. doi:10.1043/1543-2165(2007)131[242:CAOQLA]2.0.CO;2. PMID 17284109.
  5. ↑ Suzuki SO, Kitai R, Llena J, Lee SC, Goldman JE, Shafit-Zagardo B (May 2002). "MAP-2e, a novel MAP-2 isoform, is expressed in gliomas and delineates tumor architecture and patterns of infiltration". J. Neuropathol. Exp. Neurol. 61 (5): 403–12. PMID 12025943.
  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. 98. ISBN 978-0443069826.
  7. ↑ Rodriguez, FJ.; Tihan, T.; Lin, D.; McDonald, W.; Nigro, J.; Feuerstein, B.; Jackson, S.; Cohen, K. et al. (Aug 2014). "Clinicopathologic features of pediatric oligodendrogliomas: a series of 50 patients.". Am J Surg Pathol 38 (8): 1058-70. doi:10.1097/PAS.0000000000000221. PMID 24805856.
  8. ↑ Sipayya, V.; Sharma, I.; Sharma, KC.; Singh, A.. "Immunohistochemical expression of IDH1 in gliomas: a tissue microarray-based approach.". J Cancer Res Ther 8 (4): 598-601. doi:10.4103/0973-1482.106567. PMID 23361281.
  9. ↑ Fontaine D, Vandenbos F, Lebrun C, Paquis V, Frenay M (2008). "[Diagnostic and prognostic values of 1p and 19q deletions in adult gliomas: critical review of the literature and implications in daily clinical practice]" (in French). Rev. Neurol. (Paris) 164 (6-7): 595–604. doi:10.1016/j.neurol.2008.04.002. PMID 18565359.
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