Table 4.
Molecular abnormalities identified by FISH and/or Immunohistochemistry in adenoid (A-GBM), Epithelioid (E-GBM) and true epithelial (TE-GBM) glioblastomas as well as tumors that showed a sarcomatous component (GS).
| N (%) | A-GBM | E-GBM | TE-GBM | TOTAL | GS |
|---|---|---|---|---|---|
| IHC=immunohistochemistry | |||||
| P16 deletion/−9 | 6 (60) | 5 (71) | 9 (64) | 20 (65) | 11 (73) |
| −10 | 4 (40) | 5 (63) | 8 (57) | 17 (54) | 8 (53) |
| PTEN deletion | 1 (10) | 2 (25) | 4 (29) | 7 (22) | 2 (13) |
| EGFR amplification | 1 (10) | 4 (50) | 4 (27) | 9 (27) | 2 (13) |
| +7 | 7 (70) | 3 (38) | 6 (40) | 16 (48) | 9 (60) |
| RB1 deletion/−13q | 5 (50) | 0 (0) | 2 (14) | 7 (25) | 4 (31) |
| PDGFRA amplification | 1 (10) | 1 (25) | 0 (0) | 2 (7) | 1 (8) |
| P53 IHC (3+) | 4 (29) | 2 (29) | 7 (41) | 13 (34) | 6 (35) |
| P16 IHC | |||||
| Negative/weak | 4 (31) | 4 (67) | 4 (24) | 12 (33) | 7 (41) |
| Cytoplasmic only | 0 (0) | 1 (17) | 2 (12) | 3 (8) | 2 (12) |
| P21 IHC | |||||
| Negative | 6 (60) | 1 (25) | 13 (93) | 20 (71) | 11 (85) |
| P27 IHC | |||||
| Negative | 2 (20) | 1 (33) | 3 (23) | 6 (23) | 2 (15) |
| Focal | 6 (60) | 1 (33) | 8 (62) | 15 (58) | 11 (85) |
| Positive | 2 (20) | 1 (33) | 2 (15) | 5 (19) | 0 (0) |
| EGFR IHC (3+) | 3 (21) | 5 (63) | 3 (19) | 11 (29) | 3 (18) |