Table 1.
Clinicopathological and molecular features of 52 intrathoracic solitary fibrous tumors
| Case number (percentage) | |
|---|---|
| Gender | 52 |
| Male | 22 (42%) |
| Female | 30 (58%) |
| Age (range) | 52 |
| <55 | 23 (44%) |
| ≥55 | 29 (56%) |
| Locations | 52 |
| Pleura | 31 (60%) |
| Lung | 9 (17%) |
| Mediastinum/pericardium | 12 (23%) |
| Size (cm) | 50 |
| <5 cm | 17 (34%) |
| ≥5 cm | 33 (66%) |
| Histologic type | 52 |
| Conventional/cellular | 36 (70%) |
| Atypical | 8 (15%) |
| Malignant | 8 (15%) |
| Mitotic figure (/10 HPF) | 52 |
| 0 | 31 (60%) |
| 1–4 | 13 (25%) |
| >4 | 8 (15%) |
| STAT6 immunostaining intensity | 52 |
| Negative | 1 (2%) |
| Weak | 1 (2%) |
| Moderate | 5 (10%) |
| Strong | 45 (86%) |
| STAT6 immunostaining extent | 52 |
| 0 + (0%) | 1 (2%) |
| 1 + (1–24%) | 0 |
| 2 + (25–49%) | 4 (8%) |
| 3 + (50–75%) | 6 (12%) |
| 4 + (76–100%) | 41 (78%) |
| NAB2‐STAT6 RT‐PCR assay | 34/36 |
| NAB2ex4‐STAT6ex2/3 fusion variant | 29 (85%) |
| ex4‐ex2 | 28 (82%) |
| ex4‐NAB2(I)‐ex3 a | 1 (3%) |
| NAB2ex6‐STAT6ex16/17 fusion variant | 5 (15%) |
| ex6‐ex17 b | 4 (12%) |
| ex6‐ex16 | 1 (3%) |
| Poor quality | 2 |
a
This case had an intact exon 4 followed by a short stretch (8 bps) of inserted NAB2 intronic sequence and a cytosine of undetermined origin, which was then with truncated STAT6 exon 3.
b
One of these 4 solitary fibrous tumors harboring NAB2ex6‐STAT6ex17 fusion showed incorporation of one undetermined cytosine and additional 18 nucleotides from the 16th intron of STAT6 gene.