Primary pulmonary Ewing sarcoma/peripheral primitive neuroectodermal tumor

Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) is a malignant small round cell sarcoma commonly occurring among children, adolescents, and adults. We report a rare case of ES/pPNET arising from the lung in a 49-year-old woman. She was found to have a mass in the right lung on a screening imaging study for her BRCA2 mutation. A lobectomy was performed and the mass had histological, immunohistochemical, and molecular features of ES/pPNET. Few cases of primary pulmonary Ewing sarcoma have been reported.