Summary
Mediastinal anatomy
The mediastinum is the thoracic space between the visceral pleura of the lungs. The boundaries of the mediastinum are the visceral pleura, thoracic inlet (spine, first ribs, and manubrium), diaphragm, sternum, and anterior spinal ligaments. The contents of the mediastinum include the heart, great vessels, trachea, oesophagus, thymus gland, lymphatic tissue, and nerves.
The International Thymic Malignancy Interest Group (ITMIG) classification divides the mediastinum into prevascular, visceral, and paravertebral compartments (which roughly correlate to the historical anterior, middle, and posterior compartments, respectively).[1][2]
[Figure caption and citation for the preceding image starts]: Anatomical compartments of the mediastinum.From the collection of Dr Muniappan [Citation ends].
Mediastinal contents
Prevascular (anterior) mediastinal contents include:
Thymus gland
Mediastinal fat
Lymph nodes
Extracardiac aorta.
Visceral (middle) mediastinal contents include:
Pericardium, heart, ascending and descending aorta, great vessels
Trachea and carina
Lymph nodes
Oesophagus
Vagus nerves
Thoracic duct.
Paravertebral (posterior) mediastinal contents include:
Proximal intercostal vessels
Thoracic spinal ganglion
Sympathetic nerve chain
Lymph nodes.
Differentials
Common
- Thoracic aortic aneurysm
- Non-Hodgkin's lymphoma
- Metastatic cancer
- Thymoma
- Lung cancer
Uncommon
- Aortic dissection
- Hodgkin's lymphoma
- Mediastinal germ cell tumour: seminoma
- Mediastinal germ cell tumour: non-seminoma
- Thymic carcinoma
- Primary tracheal tumours
- Neurogenic tumour
- Thyroid neoplasm
- Substernal goitre
- Acute lymphocytic leukaemia (ALL)
- Chronic lymphocytic leukaemia
- Pericardial cyst
- Bronchogenic cyst
- Oesophageal cyst (includes oesophageal duplication cyst)
- Mediastinal germ cell tumour: mature teratoma
Contributors
Authors
Uma M. Sachdeva, MD, PhD
Assistant Professor of Surgery
Division of Thoracic Surgery
Massachusetts General Hospital
Harvard Medical School
Boston
MA
Disclosures
UMS declares that she has no competing interests.
Acknowledgements
Dr Uma M. Sachdeva would like to gratefully acknowledge Dr Ashok Muniappan, Dr John Kucharczuk, Dr Mario Gasparri, and Dr Nicholas Choong, the previous contributors to this topic. AM, JK, MG, and NC declare that they have no competing interests.
Peer reviewers
Marc Baker, MD, PhD
Cardiology Fellow
Department of Internal Medicine
Cardiology Division
University of Rochester
Rochester
NY
Disclosures
MB declares that he has no competing interests.
Abe DeAnda Jr., MD, FACS, FAHA
University Associate Professor
Cardiothoracic Surgery
Albert Einstein College of Medicine
Director Aortic Surgery
Montefiore Medical Center
Bronx
NY
Disclosures
AD declares that he has no competing interests.
Shahab A. Akhter, MD
Assistant Professor of Surgery
Section of Cardiac and Thoracic Surgery
The University of Chicago
Chicago
IL
Disclosures
SAA declares that he has no competing interests.
References
Key articles
Carter BW, Benveniste MF, Madan R, et al. ITMIG classification of mediastinal compartments and multidisciplinary approach to mediastinal masses. Radiographics. 2017 Mar-Apr;37(2):413-36.Full text Abstract
Detterbeck FC, Lewis SZ, Diekemper R, et al. Executive summary: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2013;143(suppl 5):7S-37S.Full text Abstract
American College of Radiology. ACR appropriateness criteria: imaging of mediastinal masses. 2020 [internet publication].Full text
Silvestri GA, Gonzalez AV, Jantz MA, et al. Methods for staging non-small cell lung cancer: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2013;143(suppl 5):e211S-50S.Full text Abstract
Reference articles
A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
Guidelines
- American College of Radiology ACR appropriateness criteria: imaging of mediastinal masses
- Managing incidental findings on thoracic CT: mediastinal and cardiovascular findings
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