Regression of mesenchymal hamartoma of the liver with sarcoma chemotherapy.

We present a young patient with metastatic Ewing sarcoma that had hepatic lesions. As we were unaware of hepatic metastases in Ewing sarcoma, liver biopsy was performed. The pathologic findings were diagnostic of mesenchymal hamartoma of the liver. Surprisingly, the combined chemotherapy for metastatic sarcoma resulted in almost complete resolution of the hamartoma in the liver. This option may be useful in extreme cases when resection is not feasible.