317 Disorders of the Mediastinum

Question 1

Contents of the anterior mediastinum?

Answer 1

the anterior mediastinum contains the thymus gland, the anterior mediastinal lymph nodes, and the internal mammary arteries and veins.

Question 2

Contents of the middle mediastinum?

Answer 2

The middle mediastinum contains the heart; the ascending and transverse arches of the aorta; the venae cavae; the brachiocephalic arteries and veins; the phrenic nerves; the trachea, the main bronchi, and their contiguous lymph nodes; and the pulmonary arteries and veins.

Question 3

Contents of the posterior mediastinum?

Answer 3

The posterior mediastinum contains the descending thoracic aorta, the esophagus, the thoracic duct, the azygos and hemiazygos veins, and the posterior group of mediastinal lymph nodes.

Question 4

What are the most common lesions in the anterior mediastinum?

Answer 4

The most common lesions in the anterior mediastinum are thymomas, lymphomas, teratomatous neoplasms,
and thyroid masses.

Question 5

What are the most common lesions in the medium mediastinum?

Answer 5

The most common masses in the middle mediastinum
are vascular masses, lymph node enlargement from metastases or granulomatous disease, and pleuropericardial and bronchogenic cysts.

Question 6

What are the most common lesions in the posterior mediastinum?

Answer 6

In the posterior mediastinum, neurogenic tumors, meningoceles, meningomyeloceles, gastroenteric cysts, and esophageal diverticula are commonly found.

Question 7

Biggest causes of acute mediastinitis?

Answer 7

Most cases of acute mediastinitis either are due to esophageal perforation or occur after median sternotomy for cardiac surgery.

Question 8

Causes of esophageal rupture?

Answer 8

The esophageal rupture can occur spontaneously

or as a complication of esophagoscopy or the insertion of a Blakemore tube.

Question 9

What is the incidence of mediastinitis after median sternotomy?

Answer 9

0.4–5.0%

Question 10

Mortality rate of acute mediastinitis?

Answer 10

exceeds 20%

Question 11

Causes of chronic mediastinitis?

Answer 11

Most cases are due to histoplasmosis or tuberculosis, but

sarcoidosis, silicosis, and other fungal diseases are at times causative.

Question 12

Signs in fibrosing mediastinitis?

Answer 12

Those with fibrosing mediastinitis usually have signs of compression of a mediastinal structure such as the superior vena cava or large airways, phrenic or recurrent laryngeal nerve paralysis, or obstruction of the pulmonary artery or proximal pulmonary veins

Question 13

Mechanisms for the development of pneumomediastinum?

Answer 13

three main causes are (1) alveolar rupture with dissection of air into the mediastinum; (2) perforation or rupture of the esophagus, trachea, or main bronchi; and (3) dissection of air from the neck or the abdomen into the mediastinum.