Table 2.
Clinico-pathological and molecular aspects of Medulloblastoma subgroups.
| Subgroup | WNT | SHH | G3 | G4 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clinico-pathological aspects | Subtype | α | β | α | β | γ | δ | α | β | γ | α | β | γ |
| Frequency | 10–15% | 28–30% | 25–28% | 40–45% | |||||||||
| Anatomic location | Cerebellopontine angle/Cerebellar peduncle | Cerebellar hemisphere | Midline (filling fourth ventricle) | Midline (filling fourth ventricle) | |||||||||
| Histology | Mostly classic, rarely LCA | Mostly ND, classic and LCA (less frequent) | Classic (most common), LCA | Classic and LCA (less frequent) | |||||||||
| Age | 6–12 | >17 | 3–17 | 0–3 | 0–3 | >17 | 0–10 | 3–17 | 0–10 | 3–17 | |||
| Metastatic disease at diagnosis | 8.6% | 21.4% | 20% | 33% | 8.9% | 8.4% | 43.4% | 20% | 39.4% | 40% | 40.7% | 38.7% | |
| Prognosis (5-year survival) | 97% | 100% | 69.8% | 67.3% | 88% | 88.5% | 66.2% | 55.8% | 41.8% | 66.8% | 75.4% | 82.5% | |
| Molecular aspects | Genetics | CTNNB1, DDX3X, KMT2D | PTCH1, TP53 KMT2D, DDX3X, MYCN ampl, BCOR, LDB1, GLI2 ampl | MYC ampl, OTX2 gain, SMARCA4, NOTCH, TGF-β | MYCN ampl, CDKN6 apml, SNCAIP duplications | ||||||||
| Chromosomal abnormalities | Monosomy of chromosome 6 | 9q deletion; loss of 10q and 17p; gain of 3q and 9p | 17q, 1q gain; loss of 5q and 10q | loss of 8, 10, 11; gain of 4, 7, 17, and 18 | |||||||||
| Genetic predisposition | APC (germline), most tumors lack CTNNB1 mutation | SUFU, PTCH1, TP53, PALB2, and BRCA2 | PALB2 and BRCA2 (rare) | PALB2 and BRCA2 (rare) | |||||||||
LCA, large cell/anaplastic; ND, nodular desmoplastic [data from Funakoshi et al. (2023)].