RESUMEN
Sarcomas are a diverse group of cancers of mesenchymal origin. Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an uncommon and hardly reported neoplasm that is a malignant variant of the typically benign inflammatory myofibroblastic tumor (IMS). We discuss an exceedingly rare case of a 53-year-old patient with primary EIMS of the pericardium who presented in impending hemodynamic collapse. A transthoracic echocardiogram revealed a large circumferential pericardial effusion with tamponade physiology and an echogenic intrapericardial mass compressing the right ventricle to near obliteration. She underwent emergent sternotomy with resection and one cycle of chemotherapy with liposomal doxorubicin before having recurrent metastatic pericardial and pleural effusions, ultimately leading to her unfortunate passing.