Table 2.
Histologic features of 40 triple-negative ET patients.
| Histologic features | N. cases (%) (n = 40) | Frequency of features in ET according to WHO 2017 |
|---|---|---|
| Cellularity | ||
| Age related increase | 5/40 (12.5%) | 10–19% |
| Granulopoiesis | ||
| Increased in quantity | 3/40 (7.5%) | <10% |
| Left shifted | 5/40 (12.5%) | <10% |
| Erythropoiesis | ||
| Increased in quantity | 10/40 (25%) | <10% |
| Left shifted | 16/40 (40%) | <10% |
| Myeloid erythroid ratio | ||
| <3:1 | 13/40 (32.5%) | NA |
| =3:1 | 26/40 (65%) | |
| >3:1 | 1/40 (2.5%) | |
| Megakaryopoiesis | ||
| Increased in quantity | 40/40 (100%) | >80% |
| Clusters | ||
| Small cluster (>3 cells) | 40/40 (100%) | 10–19% |
| Large cluster (>7 cells) | 0/40 (0%) | 0% |
| Loose cluster | 40/40 (100%) | 20–49% |
| Dense cluster | 11/40 (27.5%) | <5% |
| Size of cells | ||
| Normal/small | 37/40 (92.5%) | <5% |
| Giant | 40/40 (100%) | 20–49% |
| Morphology of cells | ||
| Hyperlobulated nuclei | 40/40 (100%) | 50–80% |
| Cloud-like/bulbous nuclei | 2/40 (5%) | <10% |
| Naked nuclei | 17/40 (42.5%) | 20–49% |
| Maturation defects | 4/40 (10%) | 0% |
| Prevalent morphology | ||
| Giant, hyperlobulated | 17/40 (42.5%) | NA |
| Polymorphic | 23/40 (57.5%) | NA |
| Fibrosis (WHO) | ||
| MF 0 | 34/40 (85%) | <5% |
| MF 1 | 5/40 (12.5%) | 0% |
| MF 2-3 | 0/40 (0%) | 0% |
| Osteosclerosis | 0/40 (0%) | |
| CD34+ vessels | ||
| Increased density | 5/40 (12.5%) | NA |
| Ectasic vessels | 16/40 (40%) | NA |
| Endoluminal hemopoiesis | 1/40 (2.5%) | NA |
| Lymphoid aggregates | ||
| Present | 8/40 (20%) | <5% |
ET, essential thrombocythemia; NA, not assessed.