Dr. Corey Kershaw: mediastinum imaging and differentials

2. Anterior Mediastinum
•Boundaries:
•sternum
•the first rib
•line following the anterior heart
border and brachiocephalic
vessels from the thoracic inlet
to the diaphragm

3. Anterior Mediastinum
•Thymus gland
•Substernal extensions of
thyroid and parathyroid glands
•Lymphatic vessels and lymph
nodes
•Connective tissue

4. Middle Mediastinum
Lower edge of the anterior heart
border along the diaphragm and
then cephalad along the
posterior heart border and
posterior wall of the trachea.

5. Middle Mediastinum
•Heart
•Pericardium
•Aortic arch and great vessels
•Innominate veins and superior
vena cava
•Trachea and main bronchi
•Hila
•Lymph nodes
•Phrenic and upper vagus
nerves
•Connective tissue

6. Posterior Mediastinum
Posterior wall of the heart and
trachea and the posterior chest
wall.

7. Posterior Mediastinum
•Esophagus
•Descending aorta
•Azygos and hemiazygos veins
•Thoracic duct
•Lymph nodes
•Vagus nerves (lower portions)
•Sympathetic chains
•Connective tissue

8. Causes of Anterior Mediastinal
Masses
• Thymic neoplasms
• Germ cell tumors
– Teratomas
– Seminomas
– Nonseminomatous
germ cell tumors
• Choriocarcinoma
• Embryonal cell
• Lymphoma
• Thyroid neoplasms
• Parathyroid
neoplasms
• Mesenchymal tumors
– Lipomas
– Lymohangiomas
– Hemangiomas

9. • Lymphadenopathy
– lymphoma
– metastatic cancer
– reactive and granulomatous inflammation (sarcoidosis)
– Angiofollicular lymphoid hyperplasia (Castleman’s disease)
• Developmental cysts
• Pericardial cyst
• Foregut duplication cysts
• Bronchogenic cyst
• Enteric cyst
• Vascular enlargements
• Diaphragmatic hernia (hiatal)
Causes of Middle Mediastinal
Masses

10. Causes of Posterior Mediastinal
Masses
• Neurogenic tumors
– Arising from peripheral nerves
• Neurofibroma
• Neurilemoma (schwannoma)
– Arising from sympathetic ganglia
• Ganglioneuroma
• Ganglioneuroblastoma
• Neuroblastoma
– Arising from paraganglionic tissue
• Meningocele
• Esophageal lesions
– Carcinoma
– Diverticula
• Diaphragmatic hernia (Bochdalek’s)