Approach to Mediastinal Masses . Clinical Presentation: 33% of all masses present in patients less than 15 years old If small, usually asymptomatic and found incidentally (cautious work up) If large, usually present with respiratory distress (frantic work up) .
Approach to Mediastinal Masses
-The anterior mediastinal compartment is bordered by the sternum anteriorly, and the ventral cardiac surface posteriorly.
-This compartment contains fat, ascending aorta, lymph nodes, internal mammary artery and vein, adjacent osseous structures (ribs and sternum), thymus.
-Therefore will most likely see masses typical to these structures, ie a lymphoma in lymph nodes.
It is located above a horizontal line drawn from the angle of Louis posteriorly to the spine.
Structures in the superior mediastinal compartment include the thyroid gland, aortic arch and great vessels, proximal portions of the vagus and recurrent laryngeal nerves, esophagus and trachea.
The borders are composed of the anterior mediastinal compartment ventrally, and the anterior surface of the spine, posteriorly.
Structures in the middle mediastinal compartment include the esophagus (which will not be visible unless there is a problem), vagus nerve, recurrent laryngeal nerve, heart, proximal pulmonary arteries and veins (hilar), trachea and root of the bronchial tree, and superior and inferior vena cava
The posterior mediastinum borders the anterior surface of the spine posteriorly to the ribs.
Structures in the posterior mediastinal compartment include the descending aorta, adjacent osseous structures (the spine and ribs) and nerves, roots, spinal cord, and the azygous and hemiazygous veins.
Case 37 - Eight year old male with a heart murmur
PA and lateral chest films show a large anterior mediastinal mass causing narrowing and rightward deviation of the trachea. The mass is not calcified.
CT exam show a low density mass in the anterior mediastinum with irregular walls with calcium in it.
Dx Teratoma, Anterior Mediastinal
Three year old male with an incidentally noted chest mass
single slice from an enhanced chest CT exam shows the mass to be non-enhancing, posterior to the right bronchi, and next to the esophagus.
Dx: Esophageal Duplication
Eighteen year old female with an incidentally noted chest mass
Esophageal duplication cyst
Eleven year old male with upper respiratory symptoms and wheezing.
Slice from an enhanced chest CT exam shows a multi-loculated non enhancing mass in the anterior mediastinum
Five year old male with cough and fever
Soft tissue in the anterior mediastinum compatible in appearance with thymus
Twelve year old female with a chest mass
PA and lateral chest films show a large, lobulated anterior mediastinal mass displacing the trachea to the right.
A chest CT exam shows the mass to extend from the neck to the diaphragm, compressing the tracheal and left mainstem bronchus leading to left lower lobe atelectasis. The chest wall mass is partially eroding the sternum and there is periosteal reaction. Axillary adenopathy is present also.
Dx:Lymphoma, Hodgkin, Anterior Mediastinal, Sternal Involvement
PA and lateral chest films show a mediastinal mass that had enlarged in the 4 year interval that may be spreading the right 5th and 6th ribs apart.
An enhanced chest CT exam shows a homogeneous mass, of fatty density, with a few septations, in the right posterior mediastinum causing some anterior displacement of the right mainstem bronchus.
Dx:Lipoma, Posterior Mediastinal
PA and lateral chest films show an anterior mediastinal mass and a large right pleural effusion.
Two contiguous slices from an enhanced chest CT exam show a homogenous, solid, anterior mediastinal mass and a large right pleural effusion.
Dx-Lymphoma, Non-Hodgkin, Anterior Mediastinal
PA and lateral chest films show a soft tissue mass in the right posterior costophrenic sulcus.
Final Diagnosis:Intrathoracic Kidney
PA and lateral chest films from the day of admission demonstrate a large round opacity in the left lower lobe that abuts the diaphragm
Two coronal T1 weighted images and one axial T2 weighted image from an MRI exam from the 5th hospital day demonstrate a posterior mediastinal mass that extends into the retrocrural regions of the chest bilaterally and that enhances uniformly. There is no evidence of metastatic disease.
large mass in the posterior mediastinum on the left.
Bone window images from a chest CT exam from the day of diagnosis demonstrate a large spherical calcified left paravertebral mass measuring 12 x 11 x 8 cm in size. There is a pleural effusion and a shift of mediastinal structures to the right. The mass appears to extend via the retrocrural space into the abdomen causing displacement of the left kidney and inferior vena cava. The mass crosses the midline. Some minimal thoracic vertebral body remodeling and rib thinning is seen on the left. No spinal canal invasion or liver metastases are seen
MRI exam performed 3 weeks after diagnosis. Coronal and sagittal T1 weighted images without contrast, and coronal and axial T2 weighted MRI images could not definitely identify the left adrenal gland, and therefore suggested it could be the origin of the midline mass. There was evidence of tumor invasion into several neural foramina and the spinal canal.
homogeneous mass abutting the right border of the heart which corresponds to a schwannoma of the right phrenic nerve.