Background: Thymoma is a rare malignant tumor of the anterior mediastinum. Thymic squamous cell carcinoma has been recognized as an aggressive form of thymoma with different behavior. It is associated with paraneoplastic syndromes, variety of clinical presentations, different way of treatment and complex prognosis. Improved imaging techniques show that an early diagnosis of thymoma is possible, which makes thymoma a potentially dangerous but preventable disease.

Methods: In this report. we describe the clinical and histological findings of a patient with incidental finding of squamouscell thymic carcinoma presented during elcc tive coronary artery bypass grafting surgery.