Dr Tai Al Akawy (consultant pediatrician Alexandria University Children's Hospital

1. ‫الرحيم‬ ‫الرحمن‬ ‫ال‬ ‫بسم‬
MEDIASTINAL SYNDROME
Dr Tai Al Akawy
Pediatrician and neonatologist
Alexandria University Children’s Hospital

2. • Compression of mediastinal structures by any
mass gives rise to a group of symptoms known
as mediastinal syndrome
• Mediastinal masses affect patients at any age
and can be asymptomatic

4. • 33% of all masses present in patients less than
15 years old
• If small, usually asymptomatic and found
incidentally
• If large, usually present with respiratory
distress

6. IntroductionIntroduction
TheThe mediastinummediastinum isis the region in the chestthe region in the chest
between the pleural cavities that contain thebetween the pleural cavities that contain the heartheart
and other thoracic viscera except the lungsand other thoracic viscera except the lungs
BoundariesBoundaries
AnteriorAnterior - sternum- sternum
PosteriorPosterior - vertebral column and paravertebral- vertebral column and paravertebral
fasciafascia
SuperiorSuperior -thoracic inlet-thoracic inlet
InferiorInferior - diaphragm- diaphragm
LateralLateral - parietal pleura- parietal pleura

7. Sternal Angle
Thoracic inlet
Thoracic oulet
Boundaries of mediastinum
sternum
Thoracic vertebra

8. TS: Mediastinum
8
CS: MediastinumCS: Mediastinum

9. ANATOMY OF MEDIASTINUM
• It is the anatomic space that lies in the
midthorax
• It is limited by the diaphragm below and the
suprasternal thoracic inlet above.
• It contains several vital structures in a small
space,
• Abnormalities can produce important
symptoms.

10. Contents of the mediastinum
The Anterior compartment contains
• The Thymus
• Substernal extensions of the thyroid
• Parathyroid glands
• blood vessels
• Pericardium
• Lymph nodes

12. Contents of the mediastinum
The middle compartment contains the
• Heart,
• Great vessels,
• Trachea,
• Main bronchi,
• Lymph nodes,
• Phrenic and
• Vagus nerves.

13. Contents of the mediastinum
The posterior compartment
• The vertebrae
• Descending aorta
• Oesophagus
• Thoracic duct
• Azygous and Hemizygous veins
• Lower portion of the vagus
• Sympathetic chains, and
• Posterior mediastinal nodes.

15. Mediastinal
masses

19. Anterior Mediastinal Masses: (4 T's)
(30% of mediastinal masses)
• Thymoma
• Teratoma
• Thyroid (Ectopic)
• (Terrible) Lymphoma

20. Thymoma
• lobulated mass in the anterior
mediastinum

21. thymoma

22. Thymoma
▪ Located in superior and / or anterior mediastinum.
▪ Can occur in all age groups but mostly seen in in adults
▪ 80 % have symptoms of myasthenia gravis
Differential diagnosis :
▪ Reactive lymphoid hyperplasia
▪ Cytological distinction between thymus and thymoma is
difficult.
▪ Follicular lymphoma
▪ PrecursorT lymphoblastic lymphoma

23. 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

24. The CT-images shows a large soft tissue mass in the anterior mediastinum, which
arises in the thymus. There is associated paratracheal adenopathy (arrow(.

25. )a) PA chest
radiograph
demonstrates a goiter
(arrow) extending
into the middle
mediastinum, causing
deviation of the
trachea to the left
(black arrowhead(.
Right-sided retrosternal goiter

26. )b) CT scan shows the mass (arrow) between the trachea and right
lung

27. Lymphoma
Lymphoma is the most
common cause of an
anterior mediastinal mass
in children and the second
most common cause of an
anterior mediastinal mass
in adults.

28. Lymphomas
–Primary mediastinal large B cell
lymphoma
–PrecursorT lymphoblastic
lymphoma/leukemia
–Anaplastic largeT cell lymphoma ,
matureT cell lymphoma.
–Hodgkin’s lymphoma.

29. In this case, enlarged lymph nodes are seen in the right
paratracheal , hilar and subcarinal areas without thymus
involvement

30. Anterior mediastinal teratoma - A large heterogenous left anterior
mediastinal mass containing soft tissue , fatty and calcific
components. Germ Cell Tumour

31. Germ cell tumors
▪ Seminoma
▪ Embryonal carcinoma
▪ Yolk sac tumors
▪ Choriocarcinoma
▪ Teratoma ; mature
▪ Teratoma; immature

33. Teratoma
▪ Most common mediastinal germ cell tumor ( 50-70 % )
– Mature teratoma : adult type tissue
– Immature teratoma: immature embryonal type of tissue;
▪ Mostly benign;
▪ Mixture of somatic tissue of 3 germ layers ; ectoderm, endoderm,
mesoderm.
▪ Immature teratoma : biphasic cell pattern ; loose aggregates of
small round cells in fibrillary matrix represents neuronal
component.
▪ Malignant transformation can occur : MC is SCC or
adenocarcinoma.

34. Embryonal carcinoma
▪ Rare type of non seminomatous germ cell tumor in young
males.
▪ Often associated with teratoma ( teratocarcinoma ),
Choriocarcinoma, or seminoma.
▪ Cytologically embryonal carcinoma is indistinguishable from
poorly differentiated carcinoma of non germ cell origin.
▪ Mitotically active tumor with malignant cells arranged in
poorly cohesive 3 D clusters , with syncitial growth pattern.
▪ Occur either as mixed or pure form. AFP levels are elevated in
all cases.

35. Yolk sac tumor / endodermal sinus
tumor
▪ Rare mediastinal tumor can occur both in paediatric ( female predilection ) as
well as in adults ( male predilection ).
▪ Commonly associated with elevated AFP levels.
▪ Coagulative tumor necrosis is abundant
▪ Schiller- Duval bodies/ Glomeruloid bodies – diagnostic are seldom seen.
▪ Identification of eosinophilic “ basal –lamina like “ substances and intra-
cytoplasmic hyaline globules ( PAS + & diastase resistant), give clue to
diagnosis.

36. Choriocarcinoma
▪ Pure medastinal choriocarcinoma is extremely rare – virtualy
non existent in children.
▪ Highly aggresive tumor.
▪ Elevated S.β HCG level.
▪ Mixture of syncytiotrophoblasts and cystotrophoblasts
against haemorrhagic background.
▪ Syncytiotrophoblastic giant cells with eosinophilic
cytoplasm , pleomorphic nuclei, prominent nucleoli,
▪ Cytotrophoblasts are medium sized cells with vaculated
basophilic cytoplasm.

37. .
Middle Mediastinal masses

38. Middle Mediastinal Masses
(30% of mediastinal masses)
• Adenopathy :
infection [bacterial, granulomatous]
neoplasm [leukemia / lymphoma, metastases]
• Bronchopulmonary or foregut malformations:
Esophageal duplication cyst,
Bronchogenic cyst,
Sequestration

39. MEDIASTINAL LYMPHADENOPATHY
• Middle mediastinum is the commonest site of intrathoracic
lymphadenopathy.
• Gross lymphadenopathy is a feature of
1)Tuberculosis
2)Histoplasmosis
3) Metastatic malignancy
4) Lymphomas
5)Sarcoidosis

40. Foregut cysts in the middle mediastinum are classified as
bronchogenic or enteric.
Bronchogenic cysts are lined by respiratory epithelium and most are
located in the subcarinal or right paratracheal area
Enteric cysts are lined by gastrointestinal mucosa and are located in
the middle or posterior mediastinum near the esophagus

41. (Right) AP radiograph shows large, smooth, homogeneous, left retrocardiac
parenchymal mass (arrows).
(Left) Axial T2 MRI shows homogeneous, well circumscribed ovoid mass (arrow) with
signal greater than CSF (curved arrow).
BRONCHOGENIC CYST

42. Enteric foregut cyst
The images show a well defined lesion in the lower mediastinum in close proximity to the
esophagus, which is typical for an enteric foregut cyst.

43. Posterior Mediastinal masses

44. NEUROGENIC TUMOURS
There are 4 histological types.
1.NEURILEMMOMA
Benign and is classically a dumbbell-shaped mass.
compress the spinal cord and produce pressure symptoms.
2.GANGLIONEUROMA
Benign, elongated and large.
Usually occurs in children but may be found at any age.
Causes flushing,hypertension,headache,sweating,diarrhoea.
3.NEUROFIBROMA
Associated with generalized neurofibromatosis
(von Recklinghausen's disease).
4.NEUROBLASTOMA
Malignant and found frequently in children.

46. Neuroblastoma

47. The CT-images show a calcified mass in the posterior mediastinum extending over several
vertebrae, which grows into the vertebral canal.
Neuroblastoma

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

49. An approach to mediastinal
syndrome and masses

50. • Epithelial tumors
– Thymoma
– Thymic carcinoma
• Germ cell tumors
– Pure GCT’s : GCT’s with only one histological type
– Mixed GCT : GCT with more than one histological type
– GCT’s with somatic type malignancy
– GCT’s with associated malignancy
WHO Classification of thymic tumors and mediastinal
tumors

51. • Mediastinal lymphomas and haematopoietic neoplasms:
– B-cell lymphoma
– T-cell lymphoma
– Hodgkin’s lymphoma
– Histiocytic and dendritic cell tumors
– Myeloid sarcoma and extra-medullary acute myeloid leukaemia
• Mesenchymal tumors of mediastinum:
– Thymolipoma
– Lipoma of mediastinum
– Liposarcoma of mediastimum
– Solitary fibrous tumors
– Synovial sarcomas

52. – Vascular neoplasms
– Rhabdomyosrcoma
– Leiomyomatous tumors
• Peripheral nerve sheeth tumors
• Ectopic tumors of mediastinum
– Ectopic tumors of thymus
– Ectopic tumors of thyroid
– Ectopic tumors of parathyroid
• Metastasis to thymus and to anterior mediastinum

55. To simplify
Benign Maliganat
Thymoma
Benign teratoma
Neurilemmnoma
Neurofibroma
Paraganglioma
Thymic carcinoama
Lymphoma
Seminoma
Embryona carcinoma
Yolk sac tumor
Choriocarcinoma
Immature teratoma
Neuroblastoma
Metastatic tumors

56. Clinical Presentation
▪ Mediastinal lesions are symptomatic in 50%-75% of patients
▪ Symptoms can be caused by local mass effects, systemic effects
of the tumor, or infection
▪ Local effects are dependent on the size and location of the lesion
and result from compression of adjacent structures
▪ Symptoms are also more common with malignant tumors
because they invade adjacent structures.

57. Organ involved Symptoms and
signs
1. Trachea, main bronchi :Stridor, dyspnoea, cough, features of
lung collapse
2. Esophagus : Dysphagia (extrinsic compression on barium
swallow)
3. Superior vena cava : Engorged non-pulsatile neck veins,
oedema and cyanosis of face, neck and arms
4. Left recurrent laryngeal nerve: Hoarseness of voice, bovine
cough
5. Phrenic nerve: Hemi-diaphragm paralysis
6. Sympathetic trunk: Horner’s syndrome

58. Specific symptoms and signs

59. Superior vena cava syndrome
Clinical manifestation resulting from
partial or complete obstruction of
the superior vena cava

60. Clinical PresentationClinical Presentation
Superior vena cavaSuperior vena cava
Vulnerable to extrinsic compression andVulnerable to extrinsic compression and
obstruction because it is thin walled andobstruction because it is thin walled and
its intravascular pressure is lowits intravascular pressure is low
Bronchogenic carcinoma and lymphomaBronchogenic carcinoma and lymphoma
are the most common etiologiesare the most common etiologies

61. Superior vena cava syndromeSuperior vena cava syndrome
Results fromResults from the increase venous pressurethe increase venous pressure
in the upper thorax , head and neckin the upper thorax , head and neck
Characterized by dilation of the collateralCharacterized by dilation of the collateral
veins in the upper portion of the bodyveins in the upper portion of the body
Edema and plethora of the face, neck andEdema and plethora of the face, neck and
upper chest, edema of the conjunctivaupper chest, edema of the conjunctiva
Cerebral symptoms such as headache,Cerebral symptoms such as headache,
disturbance of consciousness and visualdisturbance of consciousness and visual
distortiondistortion

64. Diagnostic Evaluation
• RADIOLOGY
– Plain chest x-ray taken in two planes,
posteroanterior and left lateral  basic
information about the location of the mass within
the mediastinum
– Diaphragm fluoroscopy  to evaluate paradoxical
motion of the diaphragm on rapid inspiration
indicative of phrenic nerve paralysis

65. • USG :
– via percutaneous route ; it provides both
spatial orientation as well as real time
monitoring with out exposure to radiation
– Via bronchoscopy / endoscopy via
oesophagus.
Approach to mediastinum

66. RADIOLOGY
–CT of the chest has replaced plain chest
radiography as the diagnostic procedure of
choice for mediastinal masses
–CT : locating small lesion in thoracic inlet,
hilum and middle mediastinum , via
supraclavicular, suprasternal and
parasternal approach. But continues real
time monitoring is not possible without
radiation exposure.

67. –MRI may enhance the diagnostic abilities of
chest CT
–Echocardiography and positron emission
tomography(PET) have been used 
invasive thymomas and lymphoma

68. CXR

69. Lymphoma is the most common cause of an anterior
mediastinal mass in children

74. Histologic
–FNA or needle biopsy with CT guidance of a
mediastinal mass may provide sufficient
tissue for diagnosis of thymic carcinoma or
other defined neoplasms
–Mediastinoscopy, or intrathoracic biopsy
may be considered for lymphomas in
particular, and thymomas and neural
tumors

75. The biopsy can be obtained through
• Traditional bronchoscopy or
• Echo-guided endoscopy,
• Superficial node biopsy,
• Mediastinoscopy,
• Mediastinotomy,
• Transthoracic needle biopsy,
• Thoracoscopy,
• Cervical or supraclavicular biopsies;
• Thoracotomy and sternotomy are rarely
indicated

77. Diagnosis requires combination of clinical, radiological, biochemical, and
cytomorphological information.
• Age :
In children : commonest thymic tumor is NHL. Thymoma is extremely
rare in childhood.
Adults : mets and benign mediastinal cyst of celomic origin or GI origin.
In adults : thymoma represents commonest primary thymic tumor,
followed by mediastinal lymphoma.
Approach to mediadiastinal tumors
Step 1 : clinical historyStep 1 : clinical history

78. • located in which part of mediastinum
– Extremely useful in diagnosis of tumors
– Depending on predominant cell morphology
diagnosis can be approached.
Step 2 : radiological localisationStep 2 : radiological localisation
Step 3 : cytomorphologyStep 3 : cytomorphology

79. History and relevant information for diagnosisHistory and relevant information for diagnosis

80. Treatment
Therapy should be causative

81. Mediastinal syndrome management priority is
depending on the
1. Severity of symptoms
2. Etiology
3. Prognosis

82. Supportive Care
 Elevate the patient’s head to decrease the
hydrostatic pressure and thereby the congesion
 Oxygen
 Glucocorticoid therapy (dexamethasone, every 6
hours)
 Glucocorticoids reduce the tumor burden in
lymphoma and thymoma and are therefore more
likely to reduce the obstruction
 Loop diuretics are also commonly used

83. Chemotherapy is used in lymphomas,
small-cell lung cancer and germ cell
tumors.
Besides chemotherapy,
Radiotherapy is used to shrink the tumor
mass

84. Some caSeS muSt be approached
aS an emergency
Acute lifethreatening presentation is the
only situation in which radiotherapy before
histological diagnosis can be considered.
However, this approach should be avoided, whenever
possible.
RT prior to biopsy may obscure the histologic diagnosis.

85. Current guidelines stress the importance
of accurate histologic diagnosis prior
to starting therapy,
and the use of endovascular stents in
severely symptomatic patients to
provide more rapid relief than can be
achieved using RT.
Kvale PA, Selecky PA, Prakash UB, American College of Chest Physicians.
Palliative care in lung cancer: ACCP evidence-based clinical practice
guidelines (2nd edition). Chest 2007; 132:368S.

86. Important exceptions to this general approach
are pts who present with stridor due to central
airway obstruction or severe laryngeal edema,
and those with coma from cerebral edema.

87. These situations represent a true medical
emergency, and these patients require
immediate treatment (stent placement and
radiotherapy) to decrease the risk of sudden
respiratory failure and death.

88. Radiation therapy
RT provides considerable relief by reducing
tumor burden
Symptomatic improvement is usually apparent
within 72 hours.

89. Eight year old male with a
heart murmur

91. PA and lateral chest films show
a large anterior mediastinal
mass causing narrowing and
rightward deviation of the
trachea.

92. CT exam show a low
density mass in the
anterior mediastinum with
irregular walls with calcium
in it.
Dx Teratoma, Anterior
Mediastinal

93. Three year old male with
an incidentally noted chest
mass

95. 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

96. Eleven year old male with
upper respiratory
symptoms and wheezing

98. Slice from an enhanced chest CT exam shows a multi-loculated non
enhancing mass in the anterior mediastinum
Dx-Thymic Cyst

99. Twelve year old female with a
chest symptoms and some
neck swellings
Fever ,night sweating ,loss of weight

100. PA chest films show a large, lobulated anterior mediastinal mass
displacing the trachea to the right.

101. 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.
Dx: Lymphoma, Hodgkin, Anterior Mediastinal, Sternal
Involvement

102. Fourteen year old male
presented with chest pain,
cough, dyspnea, hoarseness,
and superior vena caval
syndrome

103. Two contiguous slices from
an enhanced chest CT show
a homogenous, solid,
anterior mediastinal mass
and a large right pleural
effusion
Dx-Lymphoma
Non-Hodgkin,
Anterior Mediastinal

105. Ancillary techniques for mediastinal tumorsAncillary techniques for mediastinal tumors

106. Conclusion

107. There are multiple causes of
mediastinal masses, but the
differential diagnosis can be
narrowed based upon the
compartment involved ,the clinical
presentation , appearance of the
mass on CT scan and tissue diagnosis

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