Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 9 5 2025 04 26 229 236 Ghazaleh Salehabadi Department of Radiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Shahla Meshgi Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Hamidreza Pouraliakbar Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Azin Alizadeh Asl Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Ali Mohammadzadeh Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. 2025 02 17 2025 03 03 A Calcified Amorphous Tumor (CAT) consists of calcified nodules embedded within an amorphous fibrous material and represents an uncommon non-neoplastic intracavitary cardiac mass. In this article, we present the case of a 38-year-old Iranian gentleman who experienced a sudden loss of consciousness and right hemiparesis. Brain imaging revealed acute infarction in the left basal ganglia. Echocardiography identified a large heterogeneous echodensity in the posterior AV groove, with central echolucency extending to the base of the posterior left ventricular (LV) wall and the basal posterior mitral valve leaflet (PMVL), findings consistent with CAT. Cardiac Magnetic Resonance Imaging (CMR) demonstrated an intramural calcified mass with a necrotic core located in the lateral annulus of the mitral valve, extending into the left atrium and ventricle. The mass was deemed responsible for the cerebral infarction, which was classified as cardioembolic. This case report highlights Calcified Amorphous Tumor (CAT) as a potential embolic source, underscoring the importance of early recognition through multimodality imaging. Comprehensive management, which may include regular follow-ups or surgical intervention, is crucial for patients diagnosed with CAT. https://crcp.tums.ac.ir/index.php/crcp/article/view/1025 https://crcp.tums.ac.ir/index.php/crcp/article/download/1025/691