Cardiac tumors are rare, among which primary tumors are even rarer, and metastatic tumors are about 20 to 40 times more common than primary ones. Most of the primary cardiac tumors are benign, among which atrial mucinous tumors are the majority. 1. Benign cardiac tumors (1) Mucinous tumors Cardiac mucinous tumors account for about 50% of benign primary cardiac tumors. Age 30-50 years old, no significant difference in gender. Clinically, there are often symptoms of obstructed blood flow and embolism. The tumor occurs mostly in the left atrium (about 75% of cases), 20% in the right atrium and 5% in the ventricle. The tumors vary in size and are polypoid or villous in shape. The cut surface is gray-white translucent jelly-like, soft and friable. Microscopically, mucinous tumor cells were stellate or spindle-shaped, with ovoid or spindle-shaped nuclei. The tumor cells are sparse, scattered or in groups of three or five, and are distributed in a large mucus-like stroma that is rich in proteoglycans. The histogenesis of this tumor is still inconsistent, and many scholars believe that this tumor originates from pluripotent primitive mesenchymal cells under the endocardium. (2) Rhabdomyosarcoma Rhabdomyosarcoma of the heart is most commonly seen in children under 15 years of age, and is associated with tuberous sclerosis in about 50% of cases. Clinically, small tumors may be asymptomatic, while large tumors may protrude into the heart chambers and cause obstructive symptoms, and multiple tumors often cause severe congestive heart failure. To the naked eye, most tumors are located within the myocardium of the left and right ventricles and are often multiple, ranging from a few millimeters to several centimeters in diameter. Microscopically, the tumors are sparse, with large cells (up to 80 μm in diameter) that are ovoid in shape. The cytoplasm is vacuolated and glycogen-rich, with a central nucleus and distinct nucleoli. The cytoplasm around the nucleus is sparsely reticulated, and the cells resemble spiders, hence the name spider cells. This tumor is currently considered to be an infantile malformation derived from embryonic cardiomyoblasts. (3) Fibromas Fibromas of the heart are most commonly seen in infants and children. Clinically, it can cause symptoms of left and right ventricular outflow tract obstruction and congestive heart failure. To the naked eye, the tumor is mostly located in the left ventricle or septum. Microscopically, it is similar to other parts of fibroids. 2.Malignant tumor of heart Primary malignant tumor of heart is rarely seen, but there can be malignant hemangioendothelioma, rhabdomyosarcoma, malignant mesothelioma, fibrosarcoma, etc. 3.Metastatic tumor of the heart It is rare for malignant tumors from other parts to metastasize to the heart. However, some people think that it is not rare if it is carefully examined. Among cardiac metastases, malignant melanoma is more common. Cardiac metastases can spread from malignant tumors in neighboring organs, such as bronchial cancer, gastric cancer, esophageal cancer and mediastinal tumors, but most of them are metastases through blood channels.