Table 3.
Criteria used for classification for each diagnostic category
| G2 | WD G3 | PD small cell |
PD Large cell |
PD NOS |
|
|---|---|---|---|---|---|
| Total | 19 | 32 | 6 | 5 | 3 |
| >1 factor supporting WD No. (%) | 15 (80) | 13 (46) | 0 | 0 | 0 |
| IHC loss of DAXX or ATRX No. (%) | 0 | 6 (19) | 0 | 0 | 0 |
| DAXX, ATRX, or MEN1 mutation No. (%) | 6 (31) | 9 (28) | 0 | 0 | 0 |
| All Ki67 proliferation No. (%) rates <20% | 19 (100) | 0 | 0 | 0 | 0 |
| G1/G2 on prior biopsy or resection No. (%) | 8 (42) | 24 (75) | 0 | 0 | 0 |
| >1 factor supporting PD No. (%) | 0 | 0 | 4 (67) | 0 | 2 (67) |
| Loss of RB IHC staining No. (%) | 0 | 0 | 3 (50) | 1 (20) | 2 (67) |
| RB1, TP53, or KRAS mutation No. (%) | 12(5) | 22(32) | 1 (17) | 0 | 2 (67) |
| Adenocarcinoma component No. (%) | 0 | 0 | 0 | 0 | 0 |
| Consensus on morphology differentiation1 | 0 | 5 (16) | 1 (17) | 4 (80) | 0 |
Abbreviations: WD - well differentiated, PD - poorly differentiated, No. - Number, NOS - not otherwise specified.
1
Consensus review was used in cases without ancillary supporting information.
2
TP53 mutations were seen in 3 cases with additional criteria supporting WD.