In this developing world the mainly occurred esophageal cancer is known as ESCC i.e. Esophageal Squamous Cell Carcinoma. ESCC is considered as a significant issue related to health problems with great risks. Esophago–pericardial fistula (EPF) is an uncommon complication of esophageal disease. The development of esophago–pericardial fistulas, a life–threatening complication, is rarely reported. This is a rare case of an esophago– pericardial fistula mimicking a medical disease, which in our case is a left atrial (LA) clot. It is very difficult to differentiate between a tumor, a thrombus, and a mass in the left atrium body along with the trans–esophageal echocardiography or preoperative transthoracic. Our case report deals with two different presentations of esophageal carcinoma – esophageal CA mimicking a LA clot and esophageal CA preemption as a pericardial effusion in the same patient. In our case 52 years old male presented with acute onset shortness of breath 15 days before diagnosed as a case of LA clot with polyserositis, however cause of LA clot was not identified and referred to ourhospital.