BENIGN TERATOMA OF THE ANTERIOR MEDIASTINUM
This specimen was removed surgically from the anterior mediastinum.
The specimen is of a multi-lobulated cyst 7 cm in largest diameter, which has been bisected, the inner and outer surfaces being displayed. The inner aspect shows a fibrous-walled cyst roughly divided into compartments by fibrous partitions, some of which are fenestrated. The inner lining is generally smooth and some lipid-like deposits are also present. Superiorly the wall shows several small cystic spaces. The outer wall of the cyst shows a white shiny capsule. Sub-capsular areas of haemorrhage are most likely due to operative trauma. Histologically this was a benign cystic teratoma lined by simple columnar respiratory epithelium and in parts by a more flattened epithelium. The wall contained thymic and salivary tissue.