a case for discussion (part 2)

8/13/2019 A case for discussion (Part 2)

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A case for !!?Prof. Gamal Dawood

(Part 2)


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IMMUNOHISTOCHEMISTRY


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SNF.

Note positivity in three locations:

In neurpil (tissue located between the cell bodies of neoplastic cells);


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SNF.


Occasionally in structures suggestive of pseudorosettes of Homer Wright;


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SNF.


In the cytoplasm of some cells.


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SNF.

Homer Wright pseudorosettes

These structures are characteristic of tumors of neuronal lineage


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NeuN nuclear antigen

Advanced stages of neuronal maturation, immunolabeling is shared by many

central neurocytomas and attests to their well-differentiated nature.


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NSE.

Strong cytoplasmic positivity in part of cells, compatible with neuronal differentiation.

However, NSE (neuron-specific enolase) is, in reality, little specific, being positive also in

gliomas, as oligodendrogliomas and ependymomas.


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NSE.

Strong cytoplasmic positivity in part of cells, compatible with neuronal differentiation.

However, NSE (neuron-specific enolase) is, in reality, little specific, being positive also in

gliomas, as oligodendrogliomas and ependymomas.


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CGR.

It is observed focally in the cytoplasm.


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CGR.

It is observed focally in the cytoplasm.


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Cromogranin

Dot positivity in standard. In this case, the positivity is denoted in only a small rounded

area of cytoplasm.

It is assumed that the marking occurs in the Golgi apparatus, where the protein is being

modified after synthesis in the endoplasmic reticulum.


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Cromogranin

Dot positivity in standard. In this case, the positivity is denoted in only a small rounded

area of cytoplasm.

It is assumed that the marking occurs in the Golgi apparatus, where the protein is being

modified after synthesis in the endoplasmic reticulum.


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NF.

Negative throughout the sample. The negativity indicates that neoplastic cells,

although showing neuronal differentiation, as evidenced by the reactivity to NFC and

CGR, are in an intermediate stage. Only cells with advanced degree of differentiation

into neurons tend to be positive for neurofilament.


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Small group of astrocytes interpreted as reactive to the presence of

the tumor (non neoplastic). Have more abundant cytoplasm, with

aspect of gemistocytic astrocytes, denser and afforestation.


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GFAP.

The great majority of cells positive for GFAP are small, with short

extensions or simplified, making it unlikely that are pre-existing cells.


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GFAP

Positive cells, apparently belonging to tumor, at least in the majority.

In addition, there are fine cellular extensions attending between negative

cells.


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GFAP.

Positivity in pseudorosettes.Homer Wright pseudorosettes in this case are densely

populated by prolongations GFAP-positive, so astrocytes, make

this tumor

Astrocytic differentiation in tumor cells had been observed inseveral cases but positive GFAP filaments in pseudorosettes

never had found. Usually, these structures are positive for

neuronal markers, especially synaptophysin, but not to a glial

marker. This suggests that in intimate coexistence of rosettesthere may be an extension of two cell lines, as in normal

nervous tissue.


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GFAP. Positivity in perivascular astrocytic extensions. Small vessels in the tumor are often

surrounded by positive GFAP cellular extensions.

As in normal nervous tissue there is intimate relationship between the prolongations of

astrocytes with vessels, apparently these small primitive cells, but with incipient astrocytic

differentiation, reproduce a morpho-physiological patternof adult astrocytes.


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GFAP. Positivity in perivascular astrocytic extensions. Small vessels in the tumor are often

surrounded by positive GFAP cellular extensions.

As in normal nervous tissue there is intimate relationship between the prolongations of

astrocytes with vessels, apparently these small primitive cells, but with incipient astrocytic

differentiation, reproduce a morpho-physiological patternof adult astrocytes.


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VIM.

neoplastic cells with suspected astrocytic differentiation, as

already seen with GFAP


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VIM.




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VIM.




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.

The results with vimentin virtually reproduce with GFAP. There are marking a

portion of the small tumor cells, and of pseudorosettes of Homer Wright. The

vessels are always positive for vimentin, since this intermediate filament is

present on endothelial cells.


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.

The results with vimentin virtually reproduce with GFAP. There are marking a

portion of the small tumor cells, and of pseudorosettes of Homer Wright. The

vessels are always positive for vimentin, since this intermediate filament is

present on endothelial cells.


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VIM.

As neurons do not express this marker, the positivity for vimentin is further evidence of

astrocytic differentiation i.e. divergent differentiation in a primitive cell tumor.


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S-100.

Fuzzy Positivity, but highlighting cells that, by their extensions, suggest

astrocytic differentiation as already discussed above for GFAP and VIM


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S-100.

Fuzzy Positivity, but highlighting cells that, by their extensions, suggest

astrocytic differentiation as already discussed above for GFAP and VIM


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CD34.

This quality is excellent for demonstrating the rich vascularization. The vast network of

capillaries regularly spaced and very thin walls stands out against the tumor tissue.

There is no endothelial proliferation.


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CD34.

Positive in endothelial cells. Distributed capillary network


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CD34.

Positive in endothelial cells. Distributed capillary network


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Ki-67.

The number of cores marked was valued at around 3%, a visual estimate of multiple

fields, without counting. The photos were made in the richer areas. Mitoses are

difficult to find, even with this method.


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Ki-67.

The number of cores marked was valued at around 3%, a visual estimate of multiple

fields, without counting. The photos were made in the richer areas. Mitoses are

difficult to find, even with this method.


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Differential Diagnosis

The main differential diagnoses are : Central Neurocytoma

Oligodendroglioma: Neurocytic neoplasms are further (and mostefficiently) distinguished by a neuronal immunophenotype that includesdiffuse matrix labeling for synaptophysin and, in many instances,widespread immunoreactivity for the neuronal nuclear antigen (NeuN).This is not to dismiss evidence that oligodendrogliomas occasionallyexercise a potential for neuronal differentiation.

Chromosome 1p/19q co-deletions, a common feature of histologicallytypical oligodendrogliomas are not harbored by central neurocytomas orclear cell ependymomas

Oligodendroglioma GFAP Vimentin


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NSE Synaptophysin

Unfortunately, there does not exist at present an immunocytochemical reagent that

consistently and specifically identifies neoplastic cells as oligodendroglial. Immunolabeling

for S-100 protein, membranous Leu7 (CD57) reactivity, and cytoplasmic expression of

carbonic anhydrase Cand MAP-2 are characteristic but shared by other tumor types.


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Ependymoma

Pineocytoma

Dnet (dysembryoplasic neuroepitelial tumor):

It is a benign, mixed glial-neuronal cortical

neoplasm of children and young adults

GFAPEpendymoma


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EMAVimentin


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SynaptophysinGFAPVimentin

Central Neurocytoma


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Central Neurocytoma

a case for discussion (part 2)

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