GREB1-rearranged UTROSCTs showed significantly greater tumor diameter than did ESR1-rearranged UTROSCTs (7.2 ± 4.3 vs. 3.8 ± 3.3 cm; p = 0.002) and were less likely to display a submucosal exophytic growth (23.1% vs. 60%; p = 0.005). Here, ESR1 is linked to neoplasm.