Difference between revisions of "CNS cytopathology"
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==Technique== | ==Technique== | ||
Smears (really squash preps) are common in neuropathology. Here are some tips for getting a good smear: | Smears (really squash preps) are common in neuropathology. Here are some tips for getting a good smear: | ||
# Sampling is key -- choose 3-4 small pieces of tissue from different areas of the tissue (if there are different colours, get some of each) | # Sampling is key -- choose 3-4 small pieces of tissue from different areas of the tissue (if there are different colours, get some of each). | ||
# Keep pieces small (easier to smear) | # Keep pieces small (easier to smear). | ||
# Avoid air drying (place into formal alcohol immediately upon smearing) | # Avoid air drying (place into formal alcohol immediately upon smearing). | ||
==Basic approach== | ==Basic approach== | ||
Line 62: | Line 62: | ||
# Round nuclei with vesicular chromatin and unapparent or small nucleoli | # Round nuclei with vesicular chromatin and unapparent or small nucleoli | ||
# Visible actin striations / stress filaments in cells (seen as pink straight lines) | # Visible actin striations / stress filaments in cells (seen as pink straight lines) | ||
<gallery> | |||
File:Meningioma cytologie.jpg | HE smear of a meningioma displaying typical whorl formations (WC/jensflorian) | |||
</gallery> | |||
===Metastatic carcinoma=== | ===Metastatic carcinoma=== | ||
Line 67: | Line 71: | ||
{{Main|Metastasis}} | {{Main|Metastasis}} | ||
*[http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/_derived/Q92-Ans.htm_txt_SampleQ92.gif Squamous cell carcinoma (ouhsc.edu)].<ref>URL: [http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Q92-Ans.htm http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Q92-Ans.htm]. Accessed on: 3 November 2010.</ref> | *[http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/_derived/Q92-Ans.htm_txt_SampleQ92.gif Squamous cell carcinoma (ouhsc.edu)].<ref>URL: [http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Q92-Ans.htm http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Q92-Ans.htm]. Accessed on: 3 November 2010.</ref> | ||
*[http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Images/SampleQ50.gif | *[http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Images/SampleQ50.gif Adenocarcinoma (ouhsc.edu)]. | ||
*[http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Images/SampleQ59.gif Small cell carcinoma (ouhsc.edu)]. | *[http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Images/SampleQ59.gif Small cell carcinoma (ouhsc.edu)]. | ||
===Metastatic melanoma=== | |||
*Occasionally large bi- or multinucleated cells | |||
*Discohesive cells | |||
*Large nucleoli | |||
*Pigmented tumor cells | |||
*Accompanied by tumor infiltrating lymphocytes | |||
<gallery> | |||
File:Melanoma_CNS_met_smear_HE.jpg | Melanoma smear prep (H&E) | |||
File:Melanoma - cytology field stain.jpg | |||
</gallery> | |||
===Metastatic lymphoma=== | |||
*Small round and blue cells | |||
===Glial tumors=== | |||
* Elongated cell processes | |||
* Cohesive growth | |||
* Often attached to vasculature | |||
<gallery> | |||
File:Pilocytic astrocytoma - smear - very high mag.jpg | Pilocytic astrocytoma smear preparation (H&E) | |||
</gallery> | |||
==Things that don't smear well== | ==Things that don't smear well== |
Latest revision as of 14:59, 21 December 2016
CNS cytopathology is a subset of neuropathology and cytopathology.
An introduction to cytopathology is in the cytopathology article. Cerebrospinal (CSF) specimens are dealt with in a separate article called CSF cytopathology.
Technique
Smears (really squash preps) are common in neuropathology. Here are some tips for getting a good smear:
- Sampling is key -- choose 3-4 small pieces of tissue from different areas of the tissue (if there are different colours, get some of each).
- Keep pieces small (easier to smear).
- Avoid air drying (place into formal alcohol immediately upon smearing).
Basic approach
CNS cytology | |||||||||||||||||||||||||||||||||||||||||
Tumour | Non-tumour | ||||||||||||||||||||||||||||||||||||||||
Glial | Non-glial | Infectious | Non-infectious | ||||||||||||||||||||||||||||||||||||||
Glial | Non-glial | |
Stranding (cytoplasmic) |
thin - cannot be seen at low power (2.5x obj.), true cytoplasmic processes |
thick - can be seen at low power (2.5x obj.), artifact of smearing |
Edge of cluster | smooth/non-distinct | sharp |
Glial vs non-glial:
- Glial has cytoplasmic processes/cytoplasmic strands (stringy processes) ~ 1 micrometer thick.
- They cannot be seen well at low power.
- Cotton candy-like appearance.
- Images:
Gliosis vs. neoplasm:
- Gliosis - uniform, pink
- Astrocytoma - irregular, coarse clumps of pink fibrillary material
High grade vs. low-grade:
- Markers of high grade glioma:
- Mitoses (can see these in smear)
- Necrosis (can also see in smears)
Notes:
- Crush artifact (in smear preparation) can mimic glial processes.
- Crush artifact vs. real glial processes:
- No glial processes run perpendicular to the direction of smear.
- Glial processes may branch.
- Crushed/elongated nuclei are present in artifactual processes.
- Crush artifact vs. real glial processes:
Meningioma
Most meningiomas smear rather well, the only exception being ones that are densely fibrous.
- Key features of meningioma smears:
- Single cells or small groups of epithelioid cells with distinct cytoplasmic 'flags' (cytoplasm usually abundant)
- Round nuclei with vesicular chromatin and unapparent or small nucleoli
- Visible actin striations / stress filaments in cells (seen as pink straight lines)
Metastatic carcinoma
Typically has a 'cannonball' appearance -- with small, highly cohesive clusters of epithelioid cells.
Main article: Metastasis
- Squamous cell carcinoma (ouhsc.edu).[2]
- Adenocarcinoma (ouhsc.edu).
- Small cell carcinoma (ouhsc.edu).
Metastatic melanoma
- Occasionally large bi- or multinucleated cells
- Discohesive cells
- Large nucleoli
- Pigmented tumor cells
- Accompanied by tumor infiltrating lymphocytes
Metastatic lymphoma
- Small round and blue cells
Glial tumors
- Elongated cell processes
- Cohesive growth
- Often attached to vasculature
Things that don't smear well
Cohesive tumours:
- Neurofibroma.
- Schwannoma.[3]
- Subependymoma
- Abscess (because of fibrous capsule)
- Metastasis.[3]
Things that smear well
Dyscohesive tumours:
- Lymphoma.[3]
- Pituitary adenoma.[3]
- Oligodendroglioma.[3]
- Astrocytoma.
- Normal brain.
See also
References
- ↑ Jump up to: 1.0 1.1 URL: http://www.msdlatinamerica.com/ebooks/DiagnosticNeuropathologySmears/sid117213.html. Accessed on: 2 November 2010.
- ↑ URL: http://moon.ouhsc.edu/kfung/JTY1/NeuroTest/Q92-Ans.htm. Accessed on: 3 November 2010.
- ↑ Jump up to: 3.0 3.1 3.2 3.3 3.4 Weedman Molavi, Diana (2008). The Practice of Surgical Pathology: A Beginner's Guide to the Diagnostic Process (1st ed.). Springer. pp. 252. ISBN 978-0387744858.