How would you treat someone with unknown primary metastatic SMARCA4 deficient tumor (high-grade tumor with rhabdoid morphology)?

Ponatinib might be useful. You might also see if a clinical trial is available.

http://clincancerres.aacrjournals.org/content/24/8/1932

Consider tazemetostat (epigenetic modifier via EZH2 nhibition) via compassionate use program.