Aggressive myoepithelial carcinoma with EWSR1-POU5F1 fusion highly responsive to Ewing sarcoma combination chemotherapy.

This article describes a case of metastatic, bulky, high‐grade, rapidly progressive myoepithelial carcinoma with fusion originating from the left kidney that demonstrated a dramatic, deep response within 2 cycles of treatment with a regimen used for patients with Ewing sarcoma and an ongoing sustained response of >10 months. To the author's knowledge, this is the first report of a rapid and deep response using a systemic therapy regimen in a patient with myoepithelial carcinoma with fusion.