Table 4. Summary of histological and molecular data in the present series.
| Light microscopic findings | PXA (17) | A-PXA (2) | All (19) | Immunophenotype | PXA | A-PXA | All |
|---|---|---|---|---|---|---|---|
| Pleomorphism, n (%) | Synaptophisin, n (%) (data were insufficient in 1 case) | ||||||
| Marked | 13 (76%) | 2 (100%) | 15 (79%) | Positive | 4 (25%) | 0 | 4 (22%) |
| Moderate | 3 (18%) | 0 | 3 (16%) | Focally positive | 6 (38%) | 1 (50%) | 7 (39%) |
| None | 1 (6%) | 0 | 1 (5%) | Negative | 6 (38%) | 1 (50%) | 7 (39%) |
| Mitotic activity, n (%) | NFP, n (%) (data were insufficient in 1 case) | ||||||
| Marked | 0 | 0 | 0 | Positive | 2 (13%) | 0 | 2 (11%) |
| Moderate | 1 (6%) | 2 (100%) | 3 (16%) | Focally positive | 6 (38%) | 1 (50%) | 7 (39%) |
| None | 16 (94%) | 0 | 16 (84%) | Negative | 8 (50%) | 1 (50%) | 9 (50%) |
| Vascular proliferation, n (%) | NeuN, n (%) | ||||||
| Marked | 0 | 0 | 0 | Negative | 17 (100%) | 2 (100%) | 19 (100%) |
| Moderate | 1 (6%) | 2 (100%) | 3 (16%) | CD34, n (%) | |||
| None | 16 (94%) | 0 | 16 (84%) | Positive | 2 (12%) | 0 | 2 (11%) |
| Necrosis, n (%) | Focally positive | 7 (41%) | 0 | 7 (37%) | |||
| Marked | 0 | 1 (50%) | 1 (5%) | Negative | 8 (47%) | 2 (100%) | 10 (53%) |
| Moderate | 0 | 1 (50%) | 1 (5%) | IDH1, n (%) | |||
| None | 17 (100%) | 0 | 17 (90%) | Negative | 17 (100%) | 2 (100%) | 19 (100%) |
| Immunophenotype | Ki67 index | ||||||
| GFAP, n (%) | Median (range) | 1.9% (0.2–5.2) | 32.1% (16.7–47.5) | 2.6% (0.2–47.5) | |||
| Positive | 14 (82%) | 2 (100%) | 16 (84%) | ||||
| Focally positive | 3 (18%) | 0 | 3 (16%) | Mutation status | |||
| Negative | 0 | 0 | 0 | BRAF, n (%) (data were insufficient in 5 cases) | |||
| S-100, n (%) | V600E | 6 (50%) | 0 | 6 (43%) | |||
| Positive | 17 (100%) | 1 (50%) | 18 (95%) | 599insT | 2 (17%) | 0 | 2 (14%) |
| Focally positive | 0 | 1 (50%) | 1 (5%) | Wild-type | 4 (33%) | 2 (100%) | 6 (43%) |
| Negative | 0 | 0 | 0 | TERT promoter, n (%) (data were insufficient in 4 cases) | |||
| Nestin, n (%) | C228T | 0 | 1 (50%) | 1 (7%) | |||
| Positive | 17 (100%) | 2 (100%) | 19 (100%) | Wild-type | 13 (100%) | 1 (50%) | 14 (93%) |
| Focally positive | 0 | 0 | 0 | ||||
| Negative | 0 | 0 | 0 | ||||
PXA: pleomorphic xanthoastrocytoma.