Mediastinal Spaces Flashcards
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?
Superior mediastinal mass (e.g., lung cancer or lymphoma) causing SVC syndrome.
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?
Neurogenic tumor (e.g., schwannoma) compressing the sympathetic chain, causing Horner’s syndrome.
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?
Thymoma (most common anterior mediastinal tumor).
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?
Posterior mediastinum (e.g., esophageal cancer or neurogenic tumor).
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?
Bronchogenic cyst (a congenital middle mediastinal mass).
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?
SVC syndrome due to a mediastinal mass (e.g., lung cancer or lymphoma).
A 40-year-old woman presents with myasthenia gravis. Imaging reveals an anterior mediastinal mass. What is the most likely diagnosis?
Thymoma (associated with myasthenia gravis).
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?
Esophageal cancer or neurogenic tumor.
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?
Infected bronchogenic cyst.
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?
Lung cancer (left recurrent laryngeal nerve is more susceptible to compression due to its longer course).
A 50-year-old woman presents with dyspnea and orthopnea. Echocardiogram shows a large pericardial effusion. Where is the fluid accumulating?
Middle mediastinum (pericardial space).
A 60-year-old man presents with back pain and hypertension. CT scan shows a dilated thoracic aorta. Where is the lesion located?
Posterior mediastinum (thoracic aorta runs through the posterior mediastinum).
A 45-year-old woman presents with chylothorax after thoracic surgery. What structure was likely injured?
Thoracic duct (located in the posterior mediastinum).
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?
Anterior mediastinum (common site for germ cell tumors).
A 55-year-old man presents with dysphagia and weight loss. Endoscopy shows extrinsic compression of the esophagus. What is the most likely diagnosis?
Posterior mediastinal mass (e.g., esophageal cancer or neurogenic tumor).
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?
Middle mediastinum (common site for lymphoma).
A 50-year-old man presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a thymoma. Where is the mass located?
Anterior mediastinum (thymus is located in the anterior mediastinum).
A 35-year-old woman presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a neurofibroma. Where is the mass located?
Posterior mediastinum (common site for neurogenic tumors).
A 60-year-old man presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a bronchogenic cyst. Where is the mass located?
Middle mediastinum (common site for bronchogenic cysts).
A 45-year-old woman presents with dyspnea and a mediastinal mass on imaging. Biopsy reveals a teratoma. Where is the mass located?
Anterior mediastinum (common site for germ cell tumors like teratomas).
Front
Back
What are the divisions of the mediastinum?
Superior, anterior, middle, and posterior mediastinum.
What structures define the superior mediastinum?
Bounded by the thoracic inlet superiorly and the sternal angle (T4) inferiorly.
What are the contents of the superior mediastinum?
- Thymus, 2. Great vessels (aortic arch, SVC, brachiocephalic veins), 3. Trachea, 4. Esophagus, 5. Thoracic duct, 6. Vagus and phrenic nerves, 7. Lymph nodes.
What is the clinical significance of the thymus in the superior mediastinum?
It is the site of T-cell maturation and is associated with myasthenia gravis and thymomas.
What structures define the anterior mediastinum?
Bounded by the sternum anteriorly and the pericardium posteriorly.
What are the contents of the anterior mediastinum?
- Thymus (in children), 2. Lymph nodes, 3. Fat, 4. Internal thoracic vessels.
What is the clinical significance of the anterior mediastinum?
Common site for thymomas, lymphomas, and germ cell tumors.
What structures define the middle mediastinum?
Bounded by the pericardium.
What are the contents of the middle mediastinum?
- Heart, 2. Pericardium, 3. Ascending aorta, 4. Pulmonary trunk, 5. SVC, 6. Tracheal bifurcation, 7. Main bronchi, 8. Phrenic nerves.
What is the clinical significance of the middle mediastinum?
Common site for pericardial effusions, lymphadenopathy, and bronchogenic cysts.
What structures define the posterior mediastinum?
Bounded by the pericardium anteriorly and the vertebral column posteriorly.
What are the contents of the posterior mediastinum?
- Esophagus, 2. Thoracic aorta, 3. Azygos and hemiazygos veins, 4. Thoracic duct, 5. Vagus nerves, 6. Sympathetic chains.
What is the clinical significance of the posterior mediastinum?
Common site for esophageal tumors, neurogenic tumors, and aortic aneurysms.
What is the thoracic duct and where is it located?
The largest lymphatic vessel, located in the posterior mediastinum; drains lymph from the lower body and left upper body into the left subclavian vein.
What is the clinical significance of the thoracic duct?
Damage during surgery can lead to chylothorax (lymphatic fluid in the pleural cavity).
What is the azygos vein and where is it located?
A major vein in the posterior mediastinum that drains the thoracic wall and abdominal wall into the SVC.
What is the clinical significance of the azygos vein?
Enlargement can indicate SVC obstruction or portal hypertension.
What is the esophageal plexus and where is it located?
A network of nerves surrounding the esophagus in the posterior mediastinum, formed by the vagus nerves.
What is the clinical significance of the esophageal plexus?
Innervates the esophagus and can be affected in esophageal cancers or surgeries.
What is the sympathetic chain and where is it located?
A paired bundle of nerves in the posterior mediastinum that controls the ‘fight or flight’ response.
What is the clinical significance of the sympathetic chain?
Damage can lead to Horner’s syndrome (ptosis, miosis, anhidrosis).
What is the most common tumor in the anterior mediastinum?
Thymoma.
What is the most common tumor in the posterior mediastinum?
Neurogenic tumors (e.g., schwannomas, neurofibromas).
What is the most common tumor in the middle mediastinum?
Lymphoma.
What is the clinical significance of a mediastinal mass?
Can compress surrounding structures, leading to symptoms like dysphagia (esophagus), dyspnea (trachea), or SVC syndrome.
What is SVC syndrome?
Obstruction of the SVC, often due to a mediastinal mass, leading to facial swelling, cyanosis, and dilated neck veins.
What is the clinical significance of a widened mediastinum on chest X-ray?
Can indicate aortic dissection, aneurysm, or lymphoma.
What is the role of the vagus nerve in the mediastinum?
It provides parasympathetic innervation to the heart, lungs, and GI tract (up to the splenic flexure).
What is the role of the phrenic nerve in the mediastinum?
It provides motor innervation to the diaphragm and sensory innervation to the pericardium and pleura.
What is the clinical significance of phrenic nerve injury?
Can lead to diaphragmatic paralysis and respiratory compromise.
What is the clinical significance of a bronchogenic cyst?
A congenital cyst in the middle mediastinum that can compress airways or become infected.
What is the clinical significance of a neurogenic tumor in the posterior mediastinum?
Often asymptomatic but can cause pain or neurological symptoms if it compresses nerves.
