We present the case of a 38-year-old man who eighteen years before for having chest pain went diagnosed as hydatid cyst. It was confirmed in multislice spiral tomography (TEM) that it had a heterogeneous mass of liquid content, with partially calcified walls located in the anterior mediastinum. It was removed, being the diagnosis, by the presence of groups of acinar cells and ducts with pancreatic appearance, panqueratin and CD68 positive, of a mediastinal ectopic pancreas. A case has never been reported in Peru and in medical literature it would be the thirty-first reported case of intrathoracic ectopic pancreas.