Management of Mediastinal Tumors
Sherif Moustafa Orieby;
Abstract
Strictly speaking, the mediastinum is the partition between the lungs and includes the mediastinal pleura, the term is commonly applied to the region between the two pleural sacs. It is bounded anteriorly by the sternum and posteriorly by the thoracic vertebral column, and extends vertically from the thoracic inlet to the diaphragm.
The mediastinum is often divided into convenient compartments in an attempt to develop a differential diagnosis. However, there are no physical boundaries between compartments that limit disease.
The superior mediastinum includes all structures from the thoracic inlet superiorly to a line drawn from the lower edge of the manubrium to the lower edge of the fourth thoracic vertebra. The inferior mediastinum, which lies inferior to this line, is subsequently divided into the anterior, middle, and posterior compartments.
Mediastinum, the divisions are theoretic rather than physical. Therefore, disease can spread from one compartment to another, and some diseases do not occur exclusively in any one compartment. It is often more instructive to determine precisely where an abnormality lies. However, for ease of classification and for practicality, we have adopted the modified anatomic method of dividing the mediastinum (ie, anterior, middle, and posterior compartments with no separate superior compartment).
Tumors of the mediastinum represent a wide diversity of disease states. The location and composition of a mass is critical to narrowing the differential diagnosis.
Thymic tumors account for approximately 50% of anterior mediastinal masses, which include thymic carcinoma, which exhibit aggressive behavior, and thymomas, which manifest a more indolent course
Primary germ cell tumors (GCT) of the mediastinum are relatively rare and represent approximately 10–15% of mediastinal tumors.
Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoid tumor, representing 30%–40% of all non-Hodgkin’s lymphomas (NHLs).
Substernal goiter and ectopic thyroid tissue can appear as an anterior mediastinal mass. In most cases of substernal thyroid, an enlarged thyroid gland is palpable in the neck.
The most common masses of the middle mediastinum are lymphatic. Lymphadenopathy may result from infection, inflammation, or a primary or metastatic neoplasm.
Most posterior mediastinal masses are neurogenic. Exceptions are lymphatic, esophageal, aortic, or cystic abnormalities, and, rarely, extramedullary hematopoiesis
40% of mediastinal masses are asymptomatic. Interestingly, asymptomatic patients are more likely to have benign lesions, whereas symptomatic patients more often harbor malignancies.
The most common symptoms of presentation of mediastinal tumours are with cough, dyspnoea, and chest pain. The presence of SVC syndrome, Horner’s syndrome hoarseness of voice (due to recurrent laryngeal nerve palsy) and phrenic nerve palsy are all suggestive of malignant etiology.
Diagnosis could be done by multimodality as laboratory, imaging findings, biopsy & endoscopy
Surgical resection is the winner horse in the treatment of most of mediastinal tumors. Surgical approach to mediastinal tumor has changed during the last two decades. Median sternotmies & thoracotomies have been replaced in part by minimally invasive procedures. However when facing the narrow & difficult to reach areas of the mediastinum a minimally invasive approach using convential instruments with limited maneuverability is still challenging for many surgeons
Mediastinal tumor prognosis is varied from one to another. Mostly it is affected by pathological staging, clear margin after surgical resection, family history & neck irradiation
Most complication can be categorized into the following two groups: localizing symptoms and systemic symptoms. Localizing symptoms are secondary to tumor invasion & compression. Common localizing symptoms include respiratory compromise; dysphagia; paralysis of the limbs, diaphragm, and vocal cords; Horner syndrome; and superior vena cava syndrome. Systemic symptoms are typically due to the release of excess hormones, antibodies, or cytokines.
The mediastinum is often divided into convenient compartments in an attempt to develop a differential diagnosis. However, there are no physical boundaries between compartments that limit disease.
The superior mediastinum includes all structures from the thoracic inlet superiorly to a line drawn from the lower edge of the manubrium to the lower edge of the fourth thoracic vertebra. The inferior mediastinum, which lies inferior to this line, is subsequently divided into the anterior, middle, and posterior compartments.
Mediastinum, the divisions are theoretic rather than physical. Therefore, disease can spread from one compartment to another, and some diseases do not occur exclusively in any one compartment. It is often more instructive to determine precisely where an abnormality lies. However, for ease of classification and for practicality, we have adopted the modified anatomic method of dividing the mediastinum (ie, anterior, middle, and posterior compartments with no separate superior compartment).
Tumors of the mediastinum represent a wide diversity of disease states. The location and composition of a mass is critical to narrowing the differential diagnosis.
Thymic tumors account for approximately 50% of anterior mediastinal masses, which include thymic carcinoma, which exhibit aggressive behavior, and thymomas, which manifest a more indolent course
Primary germ cell tumors (GCT) of the mediastinum are relatively rare and represent approximately 10–15% of mediastinal tumors.
Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoid tumor, representing 30%–40% of all non-Hodgkin’s lymphomas (NHLs).
Substernal goiter and ectopic thyroid tissue can appear as an anterior mediastinal mass. In most cases of substernal thyroid, an enlarged thyroid gland is palpable in the neck.
The most common masses of the middle mediastinum are lymphatic. Lymphadenopathy may result from infection, inflammation, or a primary or metastatic neoplasm.
Most posterior mediastinal masses are neurogenic. Exceptions are lymphatic, esophageal, aortic, or cystic abnormalities, and, rarely, extramedullary hematopoiesis
40% of mediastinal masses are asymptomatic. Interestingly, asymptomatic patients are more likely to have benign lesions, whereas symptomatic patients more often harbor malignancies.
The most common symptoms of presentation of mediastinal tumours are with cough, dyspnoea, and chest pain. The presence of SVC syndrome, Horner’s syndrome hoarseness of voice (due to recurrent laryngeal nerve palsy) and phrenic nerve palsy are all suggestive of malignant etiology.
Diagnosis could be done by multimodality as laboratory, imaging findings, biopsy & endoscopy
Surgical resection is the winner horse in the treatment of most of mediastinal tumors. Surgical approach to mediastinal tumor has changed during the last two decades. Median sternotmies & thoracotomies have been replaced in part by minimally invasive procedures. However when facing the narrow & difficult to reach areas of the mediastinum a minimally invasive approach using convential instruments with limited maneuverability is still challenging for many surgeons
Mediastinal tumor prognosis is varied from one to another. Mostly it is affected by pathological staging, clear margin after surgical resection, family history & neck irradiation
Most complication can be categorized into the following two groups: localizing symptoms and systemic symptoms. Localizing symptoms are secondary to tumor invasion & compression. Common localizing symptoms include respiratory compromise; dysphagia; paralysis of the limbs, diaphragm, and vocal cords; Horner syndrome; and superior vena cava syndrome. Systemic symptoms are typically due to the release of excess hormones, antibodies, or cytokines.
Other data
| Title | Management of Mediastinal Tumors | Other Titles | الأساليب المستخدمة في علاج الأورام الحيزومية | Authors | Sherif Moustafa Orieby | Issue Date | 2015 |
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