RESUMEN
We present a 36-year-old man who presented to our emergency department with acute onset shortness of breath and syncope. He was found to have a large left atrial mass on initial computed tomography (CT) which was confirmed by echocardiography. Tumor biopsy and attempted excision were performed, showing a primary cardiac spindle cell sarcoma that was unable to be resected, to which the patient eventually succumbed to. Spindle cell sarcomas of the heart are very rare primary cardiac tumors, with a variable, non-specific presentation. The most effective treatment is surgical resection, with chemotherapy and radiotherapy showing some benefit. Despite these treatments, the prognosis is poor. Given the uncommon nature of this tumor, the objective of this report is to demonstrate the clinical presentation and CT imaging characteristics of a case of primary cardiac spindle cell sarcoma, to raise awareness of this entity, and to increase the index of suspicion as a potential differential diagnosis to cardiac tumors seen on imaging.