Mediastinal Spaces

Question 1

A 45-year-old smoker presents with hoarseness, dysphagia, and facial swelling. Chest X-ray shows a widened mediastinum. What is the most likely diagnosis?

Answer 1

Superior mediastinal mass (e.g., lung cancer or lymphoma) causing SVC syndrome.

Question 2

A 25-year-old woman presents with ptosis, miosis, and anhidrosis on one side. Imaging reveals a posterior mediastinal mass. What is the most likely cause?

Answer 2

Neurogenic tumor (e.g., schwannoma) compressing the sympathetic chain, causing Horner’s syndrome.

Question 3

A 60-year-old man presents with dyspnea and chest pain. CT scan shows a large anterior mediastinal mass. What is the most likely diagnosis?

Answer 3

Thymoma (most common anterior mediastinal tumor).

Question 4

A 50-year-old woman presents with dysphagia and weight loss. Barium swallow shows extrinsic compression of the esophagus. Where is the lesion likely located?

Answer 4

Posterior mediastinum (e.g., esophageal cancer or neurogenic tumor).

Question 5

A 30-year-old man presents with recurrent respiratory infections. CT scan reveals a cystic mass near the tracheal bifurcation. What is the most likely diagnosis?

Answer 5

Bronchogenic cyst (a congenital middle mediastinal mass).

Question 6

A 55-year-old man presents with dyspnea and distended neck veins. Chest X-ray shows a widened mediastinum. What is the most likely cause?

Answer 6

SVC syndrome due to a mediastinal mass (e.g., lung cancer or lymphoma).

Question 7

A 40-year-old woman presents with myasthenia gravis. Imaging reveals an anterior mediastinal mass. What is the most likely diagnosis?

Answer 7

Thymoma (associated with myasthenia gravis).

Question 8

A 35-year-old man presents with chest pain and dysphagia. CT scan shows a posterior mediastinal mass compressing the esophagus. What is the most likely diagnosis?

Answer 8

Esophageal cancer or neurogenic tumor.

Question 9

A 20-year-old man presents with fever and cough. Chest X-ray shows a mediastinal mass with air-fluid levels. What is the most likely diagnosis?

Answer 9

Infected bronchogenic cyst.

Question 10

A 65-year-old man presents with hoarseness and dysphagia. Imaging reveals a left-sided mediastinal mass compressing the recurrent laryngeal nerve. What is the most likely diagnosis?

Answer 10

Lung cancer (left recurrent laryngeal nerve is more susceptible to compression due to its longer course).

Question 11

A 50-year-old woman presents with dyspnea and orthopnea. Echocardiogram shows a large pericardial effusion. Where is the fluid accumulating?

Answer 11

Middle mediastinum (pericardial space).

Question 12

A 60-year-old man presents with back pain and hypertension. CT scan shows a dilated thoracic aorta. Where is the lesion located?

Answer 12

Posterior mediastinum (thoracic aorta runs through the posterior mediastinum).

Question 13

A 45-year-old woman presents with chylothorax after thoracic surgery. What structure was likely injured?

Answer 13

Thoracic duct (located in the posterior mediastinum).

Question 14

A 30-year-old man presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a germ cell tumor. Where is the mass likely located?

Answer 14

Anterior mediastinum (common site for germ cell tumors).

Question 15

A 55-year-old man presents with dysphagia and weight loss. Endoscopy shows extrinsic compression of the esophagus. What is the most likely diagnosis?

Answer 15

Posterior mediastinal mass (e.g., esophageal cancer or neurogenic tumor).

Question 16

A 40-year-old woman presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals Hodgkin’s lymphoma. Where is the mass likely located?

Answer 16

Middle mediastinum (common site for lymphoma).

Question 17

A 50-year-old man presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a thymoma. Where is the mass located?

Answer 17

Anterior mediastinum (thymus is located in the anterior mediastinum).

Question 18

A 35-year-old woman presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a neurofibroma. Where is the mass located?

Answer 18

Posterior mediastinum (common site for neurogenic tumors).

Question 19

A 60-year-old man presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a bronchogenic cyst. Where is the mass located?

Answer 19

Middle mediastinum (common site for bronchogenic cysts).

Question 20

A 45-year-old woman presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a teratoma. Where is the mass located?

Answer 20

Anterior mediastinum (common site for germ cell tumors like teratomas).

Question 21

Front

Answer 21

Back

Question 22

What are the divisions of the mediastinum?

Answer 22

Superior, anterior, middle, and posterior mediastinum.

Question 23

What structures define the superior mediastinum?

Answer 23

Bounded by the thoracic inlet superiorly and the sternal angle (T4) inferiorly.

Question 24

What are the contents of the superior mediastinum?

Answer 24

1. Thymus, 2. Great vessels (aortic arch, SVC, brachiocephalic veins), 3. Trachea, 4. Esophagus, 5. Thoracic duct, 6. Vagus and phrenic nerves, 7. Lymph nodes.

Question 25

What is the clinical significance of the thymus in the superior mediastinum?

Answer 25

It is the site of T-cell maturation and is associated with myasthenia gravis and thymomas.

Question 26

What structures define the anterior mediastinum?

Answer 26

Bounded by the sternum anteriorly and the pericardium posteriorly.

Question 27

What are the contents of the anterior mediastinum?

Answer 27

1. Thymus (in children), 2. Lymph nodes, 3. Fat, 4. Internal thoracic vessels.

Question 28

What is the clinical significance of the anterior mediastinum?

Answer 28

Common site for thymomas, lymphomas, and germ cell tumors.

Question 29

What structures define the middle mediastinum?

Answer 29

Bounded by the pericardium.

Question 30

What are the contents of the middle mediastinum?

Answer 30

1. Heart, 2. Pericardium, 3. Ascending aorta, 4. Pulmonary trunk, 5. SVC, 6. Tracheal bifurcation, 7. Main bronchi, 8. Phrenic nerves.

Question 31

What is the clinical significance of the middle mediastinum?

Answer 31

Common site for pericardial effusions, lymphadenopathy, and bronchogenic cysts.

Question 32

What structures define the posterior mediastinum?

Answer 32

Bounded by the pericardium anteriorly and the vertebral column posteriorly.

Question 33

What are the contents of the posterior mediastinum?

Answer 33

1. Esophagus, 2. Thoracic aorta, 3. Azygos and hemiazygos veins, 4. Thoracic duct, 5. Vagus nerves, 6. Sympathetic chains.

Question 34

What is the clinical significance of the posterior mediastinum?

Answer 34

Common site for esophageal tumors, neurogenic tumors, and aortic aneurysms.

Question 35

What is the thoracic duct and where is it located?

Answer 35

The largest lymphatic vessel, located in the posterior mediastinum; drains lymph from the lower body and left upper body into the left subclavian vein.

Question 36

What is the clinical significance of the thoracic duct?

Answer 36

Damage during surgery can lead to chylothorax (lymphatic fluid in the pleural cavity).

Question 37

What is the azygos vein and where is it located?

Answer 37

A major vein in the posterior mediastinum that drains the thoracic wall and abdominal wall into the SVC.

Question 38

What is the clinical significance of the azygos vein?

Answer 38

Enlargement can indicate SVC obstruction or portal hypertension.

Question 39

What is the esophageal plexus and where is it located?

Answer 39

A network of nerves surrounding the esophagus in the posterior mediastinum, formed by the vagus nerves.

Question 40

What is the clinical significance of the esophageal plexus?

Answer 40

Innervates the esophagus and can be affected in esophageal cancers or surgeries.

Question 41

What is the sympathetic chain and where is it located?

Answer 41

A paired bundle of nerves in the posterior mediastinum that controls the 'fight or flight' response.

Question 42

What is the clinical significance of the sympathetic chain?

Answer 42

Damage can lead to Horner's syndrome (ptosis, miosis, anhidrosis).

Question 43

What is the most common tumor in the anterior mediastinum?

Answer 43

Thymoma.

Question 44

What is the most common tumor in the posterior mediastinum?

Answer 44

Neurogenic tumors (e.g., schwannomas, neurofibromas).

Question 45

What is the most common tumor in the middle mediastinum?

Answer 45

Lymphoma.

Question 46

What is the clinical significance of a mediastinal mass?

Answer 46

Can compress surrounding structures, leading to symptoms like dysphagia (esophagus), dyspnea (trachea), or SVC syndrome.

Question 47

What is SVC syndrome?

Answer 47

Obstruction of the SVC, often due to a mediastinal mass, leading to facial swelling, cyanosis, and dilated neck veins.

Question 48

What is the clinical significance of a widened mediastinum on chest X-ray?

Answer 48

Can indicate aortic dissection, aneurysm, or lymphoma.

Question 49

What is the role of the vagus nerve in the mediastinum?

Answer 49

It provides parasympathetic innervation to the heart, lungs, and GI tract (up to the splenic flexure).

Question 50

What is the role of the phrenic nerve in the mediastinum?

Answer 50

It provides motor innervation to the diaphragm and sensory innervation to the pericardium and pleura.

Question 51

What is the clinical significance of phrenic nerve injury?

Answer 51

Can lead to diaphragmatic paralysis and respiratory compromise.

Question 52

What is the clinical significance of a bronchogenic cyst?

Answer 52

A congenital cyst in the middle mediastinum that can compress airways or become infected.

Question 53

What is the clinical significance of a neurogenic tumor in the posterior mediastinum?

Answer 53

Often asymptomatic but can cause pain or neurological symptoms if it compresses nerves.