2. In the name of GOD

3. Mediastinum

4. Anatomy

12. Pathology

13. Masses and mass like lesions Inflammatory changes Hematoma

14. Mediastinal masses

15. Imaging strategy Localized to mediastinum Localize within the mediastinum

16. Localize to the mediastinum Unlike lung lesions, a mediastinal mass will not contain air bronchograms. The margins with the lung will be obtuse. Mediastinal lines (azygoesophageal recess, anterior and posterior junction lines) will be disrupted. There can be associated spinal, costal or sternal abnormalities.

17. 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.

18. The lesion on the left was a pancoast tumor. The lesion on the right was a thymoma, located within the anterior mediastinum.

19. Anterior Mediastinum Thymus Teratoma (germ cell) Thyroid Terrible Lymphoma

20. ThymomaThymoma : most common primary neoplasm of the anterosuperior mediastinum Invasive thymoma Thymic carcinoma ThymolipomaThymolipoma / thymoliposarcomathymoliposarcoma Thymic cyst Benign thymic hyperplasia Thymic carcinoid Thymus

21. Thymic cyst

22. Cystic thymoma

23. Thyroid Thyroid neoplasms Thyroid goiter Parathyroid mass

24. Retrosternal thyroid

25. Retrosternal thyroid mass

27. Cervicothoracic sign

28. Lymphoma Hodgkin Lymphoma Non-Hodgkin lymphoma

29. lymphoma

30. Lymphoma (Hilum Overlay Sign: hilar vessels are seen through a mediastinal mass)

31. lymphoma

32. Germ cell tumours Mediastinal teratoma Mature:75% of mediastinal germ cell tumours Immature Teratocarcinoma Mediastinal seminoma Mediastinal emberional cell carcinoma Mediastinal yolk sac tumour Mediastinal choriocarcinoma Mediastinal mixed cell type germ cell tumour

33. Germ cell tumor

34. A fat-containing teratoma

35. Mediastinal teratoma

36. Germ cell tumor

39. Bronchogenic cyst – A benign growth with respiratory origins. Lymphadenopathy mediastinal – An enlargement of the lymph nodes. Pericardial cyst – A benign growth that results from an "out- pouching" of the pericardium (the heart’s lining). Thyroid mass mediastinal – Usually a benign growth, such as a goiter. These types of tumors can occasionally be cancerous. Tracheal tumors – These include tracheal neoplasms and non- neuplastic masses, such as tracheobronchopathia osteochondroplastica (benign tumors). Vascular abnormalities including aortic aneurysm and aortic dissection. Middle mediastinum

40. Pericardial cyst

41. Aortic aneurysm

42. Bronchogenic cyst

44. Posterior mediastinum Neurogenic tumors Neuroblastic tumors Non-neurogenic tumours Hernias

46. Neurogenic tumor

47. Neurogenic tumors Schwannoma Neurofibroma Malignant peripheral nerve sheath tumor

48. Neuroblastic tumors Neuroblastoma ganglioneuroma

49. neuroblastoma

51. Others Chordoma Pheochromocytoma Praspinal abscess Descending aortic aneurysm Esophageal neoplasm Hiatal hernia Bochdalek hernia Lymphadenopathy Extramedullary hematopoiesis Duplication cysts Thoracic meningocele

53. Extramedullary hematopoiesis

54. Bochdalek hernia

55. Intranthoracic meningocele

56. discitis

57. Foregut duplication cysts occasionally contain milk of calcium

58. 4-year-old child with stridor

59. Duplication cyst

61. Hernia hernia

63. Esophageal varicosis

64. Mediastinal widdening >8 cm in the aortic knob depression of the left main-stem bronchus deviation of the naso-gastric tube to the right apical pleural haemoatoma (cap) disruption of the calcium ring in the aortic knob (broken-halo) Aortic injury in blunt trauma

65. Mediastinal hematoma

66. Some tips in differential diagnosis of mediastinal masses

67. Thymolipoma Teratoma (Germ cell tumors) Esophageal lipoma Fat deposition Lipoma Lipoblastoma Liposarcoma Extramedullary hematopoiesis Fat containing masses

68. Hyperenhancing lymph nodes Thyroid tissue Paragangliomas Hemangiomas Vascular Etiologies Enhancing masses

69. hemangioma

70. thyroid mass

71. Melanoma Renal cell carcinoma Thyroid carcinoma Castlemann's disease Enhancing lymphomas can be seen in:

72. Castlemann's disease

73. Thymic Cyst Thymoma Teratoma Pericardial Cyst Foregut Duplication Meningocoele Neuroenteric Cyst Cystic Lymphadenopathy Lymphangioma Fluid containing masses

74. Thank you