Median Sternotomy for Mediastinal Mass Removal: Thymoma of Unknown Cause

Abstract

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.

Keywords: incidental tumor; median sternotomy; mediastinal tumor; myasthenia gravis; thymoma.

Figure 1. Preoperative CT chest with contrast

* indicates mediastinal mass

Figure 2. Left) Gross specimen of mediastinal mass measuring 10.5 x 9.2 x 3.5 cm mediastinal mass; Right) Cross-sectional cut with a firm tan-white gritty cut surface with a slightly fish-scale surface surrounded by adipose tissue

Figure 3. Post-operative chest X-ray on post-operative day one demonstrating six sternotomy wires after thymectomy, one of which is denoted by the star