CNS5:Oligodendroglioma, IDH-mutant and 1p/19q-codeleted: Difference between revisions
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This disease is <u>defined/characterized</u> as detailed below: | This disease is <u>defined/characterized</u> as detailed below: | ||
*Can be called anaplastic oligodendroglioma (historical; now known as oligodendroglioma, IDH-mutant and 1p/19q-codeleted, CNS WHO grade 3). It is discouraged to call this entity oligoastrocytoma (oligodendroglioma and astrocytoma are molecularly distinct entities. The diagnosis is reserved for rare cases where a dual genotype is identified, or where molecular testing could not be completed). | |||
*A molecularly defined diffusely infiltrating glioma with IDH1 or IDH2 mutation and codeletion of chromosome arms 1p and 19q<ref name=":0" /> . | *A molecularly defined diffusely infiltrating glioma with IDH1 or IDH2 mutation and codeletion of chromosome arms 1p and 19q<ref name=":0" /> . | ||
*Oligodendrogliomas are graded morphologically as either CNS WHO grade 2 or CNS WHO grade 3. | *Oligodendrogliomas are graded morphologically as either CNS WHO grade 2 or CNS WHO grade 3. | ||
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The <u>sites of involvement</u> of this disease are detailed below: | The <u>sites of involvement</u> of this disease are detailed below: | ||
* Approximately 60% of oligodendrogliomas occur within the frontal lobes with | *Approximately 60% of oligodendrogliomas occur within the frontal lobes with | ||
** 14-16% in the temporal lobe | **14-16% in the temporal lobe | ||
** 10-15% in the parietal lobe | **10-15% in the parietal lobe | ||
** 1-6% in the occipital lobe | **1-6% in the occipital lobe | ||
** Less commonly basal ganglia / cerebellum brainstem | **Less commonly basal ganglia / cerebellum brainstem | ||
* Leptomeningeal spread and gliomatosis cerebri pattern can rarely occur | *Leptomeningeal spread and gliomatosis cerebri pattern can rarely occur | ||
* Rare spinal lesions have been reported but lack genotyping to confirm true oligodendroglioma | *Rare spinal lesions have been reported but lack genotyping to confirm true oligodendroglioma | ||
* Extracranial metastasis exceedingly rare (CNS WHO grade 3) | *Extracranial metastasis exceedingly rare (CNS WHO grade 3) | ||
The <u>morphologic features</u> of this disease are detailed below: | The <u>morphologic features</u> of this disease are detailed below: | ||
* Classically consist of cells with round, monomorphous nuclei with stippled chromatin and perinuclear halos (artifactual fried-egg appearance) | *Classically consist of cells with round, monomorphous nuclei with stippled chromatin and perinuclear halos (artifactual fried-egg appearance) | ||
** Intervening delicate “chicken wire” vasculature | **Intervening delicate “chicken wire” vasculature | ||
** Can contain GFAP-positive minigemistocytes | **Can contain GFAP-positive minigemistocytes | ||
** Often contain microcalcifications, especially in low-grade tumors<ref name=":0" /> | **Often contain microcalcifications, especially in low-grade tumors<ref name=":0" /> | ||
The <u>immunophenotype</u> of this disease is detailed below: | The <u>immunophenotype</u> of this disease is detailed below: | ||