A Rare Case of Primary Cardiac Undifferentiated Pleomorphic Sarcoma with Brain Metastases

Abstract Introduction/Objective Undifferentiated pleomorphic sarcomas are highly malignant undifferentiated fibroblastic tumors with an aggressive clinical course. Primary cardiac undifferentiated pleomorphic sarcomas are extremely rare (incidence < 0.1%) and most commonly occur in the left atrium. We report a case of a left atrial undifferentiated pleomorphic sarcoma that was thought to be a cardiac myxoma on imaging studies. Methods/Case Report A 22-year-old female without past medical or family history presented to the emergency department for a cerebrovascular accident. During clinical work up, transesophageal echocardiogram revealed a 3 cm mass attached to left atrial septum and a 1.8 cm mass attached to the interatrial septum with associated thrombus formation. The patient underwent surgical excision of the mass. Histological analysis revealed a tumor comprised of spindle and epithelioid cells with abundant nuclear atypia, mitotic figures, and necrosis. Extensive immunohistochemical analysis did not show specific lineage and the tumor was classified as an undifferentiated pleomorphic sarcoma. Two months after initial surgery, the patient presented with additional neurologic deficits and brain lesions. The pathologic findings in the brain biopsy specimen were identical to those in the cardiac specimen and consistent with metastatic undifferentiated pleomorphic sarcoma. This case provides insight into the metastatic behavior of high-grade cardiac sarcomas and their unusual clinical and radiographic presentations, including neurologic manifestations that are unique to the primary cardiac location of the tumor. Results (if a Case Study enter NA) NA Conclusion In conclusion, because the majority of cardiac undifferentiated pleomorphic sarcomas occur in the left atrium, these growths can be mistakenly diagnosed as benign myxoma preoperatively. This case provides insight into the metastatic behavior of high-grade cardiac sarcomas and their unusual clinical and radiographic presentations, including neurologic manifestations that are unique to the primary cardiac location of the tumor.