Table 1. Immunophenotypic features and differential diagnoses of pediatric-type diffuse low-grade gliomas.
MYB: V-myb avian myeloblastosis viral oncogene homolog; MYBL1: V-myb avian myeloblastosis viral oncogene homolog-like 1; IDH1: Isocitrate dehydrogenase 1; GFAP: Glial fibrillary acidic protein; ATRX: Alpha-Thalassemia mental retardation syndrome X-linked; BRAF: B-Raf proto-oncogene, serine/threonine kinase; Olig-2: Oligodendrocyte lineage transcription factor 2; EMA: Epithelial membrane antigen; CD34: Cluster of Differentiation 34, MN-1: Meningioma 1 proto-oncogene; H3F3A G34R/V: H3.3 histone A, mutation where glycine at position 34 is replaced by arginine [R] or valine [V]; H3K27M: surrogate immunomarker for mutation in H3F3A or HIST1H3B/C gene where lysine 27 is replaced by methionine; DNET: Dysembryoplastic neuroepithelial tumor
| Tumor Type | Marker | Result/Status | Differentials |
| Diffuse Astrocytoma, MYB/MYBL1-Altered | IDH1 p.R132H | Negative | Astrocytoma, IDH-mutant |
| GFAP | Positive | Astrocytoma, IDH-wild type | |
| ATRX | Retained expression | Angiocentric glioma | |
| EMA | Dot-like intracytoplasmic [14] | Ganglioglioma | |
| CD34 | Negative | CD34-negative gliomas | |
| Ki-67 Proliferation Index | < 1% | Low proliferative index gliomas | |
| Angiocentric Glioma | IDH1 p.R132H | Negative | Astroblastoma, MN-1, altered |
| GFAP | Positive | Astrocytoma, IDH-mutant | |
| EMA | Perinuclear dot-like | Astrocytoma, IDH-wild type | |
| Olig-2 | Negative | Ependymoma | |
| Ki-67 Proliferation Index | < 1–5% [16,18,20] | Low-grade glioma | |
| Polymorphous Low-Grade Neuroepithelial Tumor of the Young (PLNTY) | IDH1 p.R132H | Negative | Astroblastoma, MN-1, altered |
| GFAP | Positive | Astrocytoma, IDH-mutant | |
| Olig-2 | Positive | Astrocytoma, IDH-wild type | |
| CD34 | Positive | Ependymoma | |
| ATRX | Retained expression | ATRX-retained gliomas | |
| BRAFp.V600E | Positive (in up to 54% of cases)[19, 45-48] | BRAF-mutant low-grade gliomas | |
| Diffuse Low-Grade Glioma, MAPK Pathway-Altered | IDH1 p.R132H | Negative | Pilocytic astrocytoma |
| GFAP | Positive | DNET | |
| Olig-2 | Positive | Ganglioglioma | |
| BRAFp.V600E | Positive | BRAF-driven tumors | |
| H3F3A G34R/V | Negative | Excludes G34R/V mutant gliomas | |
| H3K27M | Negative | Excludes midline glioma, H3K27-altered |