Median Sternotomy for Mediastinal Mass Removal: Thymoma of Unknown Cause.

Thymoma is a rare mediastinal malignancy. Although it may often be associated with paraneoplastic syndromes such as hypogammaglobulinemia, pure red cell aplasia, or myasthenia gravis (MG), some thymomas may also be idiopathic in origin. Although thymoma is the most common mass found in the anterior mediastinum, its rarity still proves difficult in swift diagnosis and subsequent treatment. This case presents a patient with an unknown anterior mediastinal mass incidentally found on imaging, with the final diagnosis of thymoma made from a pathologic investigation that was performed post-sternotomy and resection.