shivam cp 26 aug mediastinam masses.pptx

Mediastinal mass case presentation radiology

1. Case Presentation Dr. Shivam Agrawal JR 1 Radiology

2. A 70 year old male came with complaint of breathlessness since 1 year and cough since 5 days.

3. Differential Diagnosis 1. Mediastinal Mass Anterior Middle Posterior 2. Pulmonary mass

4. Anterior mediasitinal mass Differentials Thymus Teratoma (germ cell) Thyroid Terrible Lymphoma

5. Anterior mediasitinal mass Differentials Lesions Fluid Fat Vascular Thymic Lymphoma Thymic C (cyst) Germ cell—benign Thyroid Germ Cell Pericardial C (cyst) Thymolipoma Cardiac/Coronary Goiter Germ Cell C (cystic) Fat Pad

6. Clues to locate mass to mediastinum Mediastinal masses are lined by parietal pleura, so will have : Masses in the lung parenchyma typically: Smooth contour Mediastinal mass will create obtuse angles with the lung . Not contain air bronchograms May be seen bilaterally Mediastinal lines will be disrupted Are surrounded by air A lung mass abutts the mediastinal surface and creates acute angles with the lung May contain air bronchograms Will be on one side only

7. LEFT: A lung mass abutts the mediastinal surface and creates acute angles with the lung. RIGHT: A mediastinal mass will sit under the surface of the mediastinum , creating obtuse angles with the lung

8. Mediastinal masses

9. Approach Is the mass actually in the mediastinum or is it in the lung? If in the mediastinum, then in which compartment? What is the differential diagnosis for the mass?

10. PA and lateral chest films are the first step in distinguishing from which mediastinal compartment the mass is arising from. CT & MRI is the next step, better characterizing the nature and extent of the lesion, thus narrowing the differential diagnosis. Tissue biopsy is required for definitive diagnosis, and surgical resection for definitive cure. Investigations

11. Mediastinal Boundaries Compartment Anteriorly Posteriorly Anterior Sternum Anterior aspect of trachea and posterior margin of heart Middle Anterior aspect of trachea and posterior margin of heart A vertical line drawn along the thoracic vertebrae 1 cm behind their anterior margins Posterior Vertical line drawn along the thoracic vertebrae 1 cm behind their anterior margins Costovertebral junction A M P The Felson method of division is based on findings at lateral chest radiography

12. IMTG CLASSIFICATION of MEDIASTINAL COMPARTMENTS

13. Which compartment? Many mediastinal reflections can be appreciated at conventional radiography (CR), and their presence or distortion is the key to the interpretation of mediastinal abnormalities . Hilum overlay and convergence signs Paratracheal stripe Azygo-oesophageal recess Paraspinal Lines Cervicothoracic sign Thoracoabdominal sign Anterior Junction line Posterior Junction Line Effect on adjacent structures Trachea - deviation or narrowing of trachea seen with anterior compartment masses Ribs - bony destruction seen with posterior compartment masses

14. Hilum overlay and convergence signs Principle of hilum overlay The proximal segments of the R and L main pulmonary arteries lie lateral to the cardiac silhouette on PA film An anterior mediastinal mass will overlap the main pulmonary arteries, therefore they will be seen within the margins of the mass Hilum convergence To distinguish between enlarged pulmonary artery and mediastinal mass If branches of the pulmonary artery converge toward a central mass - enlarged PA If branches of PA converge toward the heart rather than the central mass - mediastinal tumor

15. Hilum can be seen through mass This must be an anterior mediastinal mass because it overlaps rather than “pushes out” the main pulmonary arteries This particular example is a thymoma

16. Cervicothoracic sign Described by Felson : “If a thoracic lesion is in anatomic contact with the soft tissues of the neck, its contiguous border will be lost.” The anterior mediastinum ends at the level of the clavicles. The posterior mediastinum extends much higher. Therefore any mass that remains sharply outlined in the apex of the thorax must be posterior and entirely within the chest, and  any mass that disappears at the clavicles must be anterior and extends into neck

17. See sharp margin above clavicle Mass is in posterior mediastinum . It remains sharply outlined in apex of thorax, indicating that it is surrounded by lung. This particular example is a gang

18. Thoracoabdominal sign A sharply marginated mediastinal mass seen through the diaphragm must lie entirely within the chest. The posterior costophrenic sulcus extends far more caudally than the anterior aspect of the lung Therefore Any mass that extends below the dome of the diaphragm and remains sharply outlined must be in the posterior compartments and surrounded by lung, and Any mass that terminates at dome of diaphragm must be anterior

19. Outline of the Mass can be seen below diaphragm Margin of mass is apparent and below diaphragm, therefore this must be in the middle or posterior compartments where it is surrounded by lung This example is a ‘Lipoma ’

20. Right Paratracheal stripe The right paratracheal stripe is seen projecting through the SVC. It is formed by the trachea, mediastinal connective tissue, and paratracheal pleura and is visible due to the air–soft tissue interfaces on either side. Paratracheal stripe should be uniform in width with a normal width ranging from 1 to 4 mm. Right paratracheal stripe 5 mm or more in width is considered widened. The azygos vein lies at the inferior margin of the right paratracheal stripe at the tracheobronchial angle.

21. Lymphadenopathy . On a collimated posteroanterior chest radiograph,the right paratracheal stripe is not seen, having been obliterated by a right paratracheal mass (arrowheads). CT scan demonstrates right paratracheal Lymphadenopathy (arrow), which obliterates the air–soft tissue interface between the right lung and the tracheal wall..

22. Azygoesophageal Recess The azygoesophageal recess is the interface between the right lung and the mediastinal reflection, with the esophagus lying anteriorly and the azygos vein posteriorly within the mediastinum . On X- ray,it appears as a line – - in its upper 1/3 rd , it deviates to the right at the level of the carina to accommodate the azygos vein arching forward. - middle 1/3 rd , the line has a variable appearance: It is usually straight or a minimal convexity to the right may be seen in adults - lower 1/3 rd , usually straight. ( air in esophagus ) . It has an interface with the middle mediastinum ; thus, the resulting line seen at radiography can be interrupted by abnormalities in both the middle and posterior compartments.

23. Azygoesophageal recess reflection. (a) Posteroanterior chest radiograph shows the azygoesophageal line (arrowheads). (b) CT scan shows the azygoesophageal recess (white arrow) formed by the esophagus anteriorly (black arrow) and theazygos vein posteriorly (arrowhead).

24. Paraspinal Lines The paraspinal lines are created by the interface between lung and the pleural reflections over the vertebral bodies. The left paraspinal line is much more commonly seen than the right. The descending aorta holds the pleural reflection off the vertebral body, allowing the lung–soft tissue interface to be more tangential to the x-ray beam. On the right, the pleural reflection is more often oblique to the x-ray beam and therefore less commonly seen. The paraspinal lines are disrupted by paravertebral disease—which commonly includes diseases originating in the intervertebral disks and vertebrae—and by neurogenic tumors .

25. (a) On a collimated posteroanterior chest radiograph, the left paraspinal line (arrow) is seen separate and distinct from the vertebral body (black arrowhead) and the descending thoracic aorta (white arrowhead). (b) CT scan shows the left paraspinal line. The descending aorta holds the pleural reflection (arrow) away from the vertebral body, which allows the lung–soft tissue interface to be more tangential to the x-ray beam and therefore visualized as a line. (c) Collimated posteroanterior radiograph shows the right paraspinal line (arrow).

26. Anterior Junction line The anterior junction line is seen at posteroanterior chest radiography. The line is formed by the anterior apposition of the lungs and consists of the four layers of pleura separating the lungs behind the upper two-thirds of the sternum There is a variable amount of fat between these layers that can affect the thickness of the anterior junction line. The line runs obliquely from upper right to lower left and does not extend above the manubriosternal junction.

27. Anterior junction line. Posteroanterior chest radiograph demonstrates the anterior junction line (arrow). (b) Computed tomographic (CT) scan shows the four layers of pleura that constitute the anterior junction line (arrow). The interface between aerated lung and pleura allows the line to be appreciated at conventional radiography

28. Posterior Junction Line The posterior junction line is a posterior mediastinal line that is seen above the level of the azygos vein and aorta and that is formed by the apposition of the lungs posterior to the esophagus and anterior to the vertebral bodies, usually the third to fifth thoracic vertebrae. Like the anterior junction line, it consists of four layers of pleura. It appears as a thin straight line projecting through the trachea, unlike anterior junction line, it can be seen above the clavicles.

29. Collimated posteroanterior chest radiograph shows the posterior junction line (arrow) projecting through the tracheal air column. (b) CT scan shows the posterior junction line (arrow), which is formed by the interface between the lungs posterior to the mediastinum and consists of four pleural layers.

30. Anterior Mediastinal lesion Silhoutte with right cardiac border, ascending aorta Obliteration of anteriro junctional line Hilum overlay Obliteration of cardiophrenic angle and retrostenal space Mass effect on trachea Preseravtion of posterior mediastinal lines

31. Middle Mediastinal lesion Widening of paratracheal stripes Mass effect on trachea Convex border of the AP window Distiortion of the azygoesophageal recess on right

32. Posterior Mediastinal lesion Distortion of paraspinal lines Posterior ribs or vertebral erosion/swelling Cervicothroacic sign Obliteration of posterior junction line and descending aorta Distiortion of the azygoesophageal recess

33. Thank you