Chest_003

A 22 year old female has a CXR performed for chest pain. This reveals an opacity adjacent to the left cardiophrenic angle and CT is advised. CT thorax demonstrates a homogenously hypodense (HU -75) mass over the left pericardium and diaphragm. There is no evidence of invasion or mediastinal lymphadenopathy.
What is the most likely diagnosis?

Correct Answer: 
Thymolipoma

Liposarcoma

Teratoma

Thymolipoma

Mediastinal lipomatosis

Oesophageal lipoma

Thymolipomata are usually incidentally discovered on imaging of the chest for other reasons. They may however present with dyspnoea, chest pain or cough. Imaging characteristics are as described, they may also have some heterogeneity due to thymic soft tissue within the mass. Liposarcoma are generally of higher attenuation and less homogenous, as are teratomas. Mediastinal lipomatosis more often occurs in the upper mediastinum. Oesophageal lipomas tend to arise within the lumen of the oesophagus and cause dysphagia.