Left atrial mass: a rare presentation of spindle cell sarcoma

SESSION TITLE: Cardiovascular Disease: Potpourri SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/11/2023 09:40 am - 10:30 am INTRODUCTION: Soft tissue sarcomas are a rare and heterogeneous group of malignant mesenchymal tumors originating throughout the body with over 100 histological subtypes. Prevalence of primary cardiac sarcomas is exceedingly rare with an incidence between 0.001 to 0.030%, while the prevalence of cardiac metastasis is 20-40 times higher. These rare tumors frequently have a poor prognosis despite surgical resection due to high-grade dysplasia, frequent recurrence, and predilection for distant metastasis. Here we discuss a rare case of hilar spindle cell sarcoma with extensive vascular invasion and disruption, presenting as a left atrial mass. CASE PRESENTATION: A 51-year-old woman with a history of recurrent unprovoked pulmonary embolism reported progressive symptoms of palpitations, chest pain, and shortness of breath. An outpatient echocardiogram identified a 7 cm left atrial (LA) mass flailing through the mitral valve, prompting an emergent transfer to the emergency department (Figure 1). Collectively a CT angiogram of the chest, repeat echocardiogram (TTE), and chest MRI delineated a 5.0 x 8.5 x 5.0 cm right hilar mass, extensive saddle pulmonary embolism, and massive thrombus attached to the right upper pulmonary vein extending into the LA. (Figure 2-3) Left ventricular ejection fraction (LVEF) was 60 to 65%, with no wall motion abnormalities and grade 1 diastolic dysfunction, and RVSP 53 mmHg was noted on TTE. Successful percutaneous thrombectomy was completed, followed by bronchoscopy and biopsy. Core needle biopsies showed indeterminate type-spindle cell malignant neoplasm. The patient was started on AIM therapy consisting of liposomal Doxorubicin, Ifosfamide, and Mesna. During the treatment course, the patient briefly suffered mildly depressed LVEF to 40-45%, treated with low-dose lisinopril and metoprolol. After 6 cycles of AIM, a decrease in left atrial tumor size to 1.45 x 3.78 cm and an improvement of LVEF 50-55% was confirmed on chest CT and TTE, respectively. DISCUSSION: Differential diagnosis of intracardiac masses include thrombi, vegetation, primary or secondary cardiac tumors, and normal anatomic variants such as Chiari network. Our case presents another differential to consider: primary local soft tissue tumor with vascular invasion into the heart. Cardiac masses can cause a multitude of symptoms through embolization, obstruction leading to heart failure or valvular dysfunction, direct invasion causing impaired ventricular function, arrhythmias, and heart block. Left atrial masses can particularly lead to symptoms of obstruction, mitral stenosis, mitral regurgitation, heart failure, as well as pulmonary hypertension. CONCLUSIONS: Cardiac invasion of localized spindle cell sarcoma is an incredibly rare presentation of a left atrial mass. Maintaining a broad differential diagnosis, early detection, and diagnostic sampling with timely initiation of treatment can help prevent the progression of cardiac complications. REFERENCE #1: Gamboa AC., Gronchi A. and Cardona K. (2020), Soft-tissue sarcoma in adults: An update on the current state of histiotype-specific management in an era of personalized medicine. CA A Cancer J Clin, 70: 200-229. https://doi.org/10.3322/caac.21605 REFERENCE #2: Reynen K. Frequency of primary tumors of the heart. Am J Cardiol. 1996 Jan 1;77(1):107. doi: 10.1016/s0002-9149(97)89149-7. PMID: 8540447. REFERENCE #3: Orlandi A, Ferlosio A, Roselli M, Chiariello L, Spagnoli LG. Cardiac Sarcomas: An Update. Journal of Thoracic Oncology. Volume 5, Issue 9, 2010. Pages 1483-1489. ISSN 1556-0864. https://doi.org/10.1097/JTO.0b013e3181e59a91. DISCLOSURES: No relevant relationships by Muhammad Arif No relevant relationships by Dr. Pallavi Bellamkonda No relevant relationships by Ali Moradi No disclosure on file for Abdulbaril Olagunju No relevant relationships by Austin Saugstad No relevant relationships by Beeletsega Yeneneh