Abstract
Primary pulmonary Ewing sarcoma is an extremely rare tumor of neuroectodermal tissue. In this article, we report on the case of a 45-year-old female who presented in the emergency department with shortness of breath and night fever. Radiologic findings suggested a massive pulmonary mass and a metastatic liver lesion. The diagnosis of Ewing sarcoma was established through a percutaneous biopsy of the lung mass and liver lesion. We highlight the importance of considering a broad differential diagnosis for a large pulmonary mass in order to lead to a prompt diagnosis and treatment.