Mediastinum (ITMIG classification)
The International Thymic Malignancy Interest Group (ITMIG) classification of mediastinal compartments was developed to reflect a division of the mediastinum based on cross-sectional imaging. It was in part an effort to consolidate prior discrepant classification systems in use by different medical specialties. A working group composed of approximately 225 experts in thoracic surgery, medical oncology, diagnostic radiology, and pathology were tasked with forming a practical system for anatomic classification which unified the various systems.
Classification
The ITMIG classification divides the mediastinum into three compartments: prevascular, visceral and paravertebral .
Prevascular compartment
Boundaries
- superior: thoracic inlet
- inferior: diaphragm
- anterior: posterior cortex of the sternum
- lateral: parietal mediastinal pleura
- posterior: anterior aspect of the pericardium
Contents
- thymus
- lymph nodes
- left brachiocephalic vein
- fat
Visceral compartment
Boundaries
- superior: thoracic inlet
- inferior: diaphragm
- anterior: posterior boundary of the prevascular compartment
- posterior: a vertical line connecting a point on each thoracic vertebral body 1 cm posterior to its anterior margin (visceral-paravertebral compartment boundary line)
Contents
- trachea/carina
- esophagus
- lymph nodes
- heart
- ascending aorta; aortic arch; descending thoracic aorta
- superior vena cava
- intrapericardial pulmonary arteries
- thoracic duct
Paravertebral compartment
Boundaries
- superior: thoracic inlet
- inferior: diaphragm
- anterior: posterior boundaries of the visceral compartment
- posterolateral: vertical line against the posterior margin of the chest wall at the lateral margin of the thoracic spine
Contents
- thoracic spine and paravertebral soft tissues
