Abstract
Left atrial masses are most commonly diagnosed as myxomas. When clinicians doubt the diagnosis, a biopsy is warranted. However, this can be very difficult with left-sided tumors. We present a 71-year-old woman with a presumed left atrial myxoma with features concerning for a malignant lesion. She underwent a computed tomography-fluoroscopy-guided percutaneous biopsy, revealing a diagnosis of malignant spindle cell neoplasm, thus avoiding surgery and allowing for early treatment.