Spindle cells with fascicular-storiform pattern
Pale eosinophilic cytoplasm
Ovoid nuclei with small nucleoli; conspicuous mitotic activity
Collagenous stroma; variably-sized blood vessels with occasional perivascular hyalinization
IHC: SATB2, cyclin D1
RNA-seq: VIM::KMT2A gene fusion
PMID: 31136005, 31592798, 32461620