4 MediastinumThe superior mediastinum lies between the manubrium and thoracic vertebrae one to four.The anterior mediastinum is bounded by the sternum anteriorly and pericardium posteriorly.The middle mediastinum consists of the heart and vascular structures; anything in the middle of the chest that is radio dense on lateral radiograph is within the middle mediastinum.The posterior mediastinum lies between the heart and the vertebral bodies.
5 Subdivision of mediastinum anterior mediastinummiddle mediastinumposterior mediastinum
6 Mediastinal LesionsAny lesion that occurs in the mediastinum – can be focal or diffuse.CT scan or MRI with contrast is usually indicated for further evaluation.
7 Mediastinal Lesions Focal vs Diffuse AnthraxThymoma in patient with Myasthenia Gravis AnthraxFocal lesions are caused by massesDiffuse lesions are caused by infection, bleeding or infiltrating tumorThymoma
8 1. Superior Mediastinum Aortic Arch & its branches Brachiocephalic and subclavian vesselsSuperior vena cava upper half & tributariesTracheaThyroidOesophagusThoracic ductPhrenic ,Vagus ,Cardiac, Lt.Recurrent L nerves
13 anterior lesion. Lymphoma Mediastinal LesionsAnterior lesions – thymoma, thyroid lesions, teratoma, t-cell lymphomas, and lymphadenopathy.Usually seen in retrosternal space.anterior lesion. LymphomaPos silhouette sign with L heart border indicating that this is an anterior lesion. Lymphoma in a 13 yr old boy who was complaining of testicular swelling. Since systemic diseases such as lymphoma may present as a testicular mass, a chest radiograph was obtained. The common causes of testicular swelling with a mediastinal mass include lymphoma, leukemia and germ cell tumors.
14 Mediastinal LesionsLateral view shows a solid tissue density in the region anterior and superior to the heart.Lymphoma is the most common anterior mediastinal mass.Lymphoma
15 Middle Mediastinal Mass 3. Middle MediastinumMiddle mediastinumMiddle Mediastinal MassHeart and pericardiumAscending aortaSuperior vena cavaAzygous veinPhrenic and vagus nervesTracheaTrachea Bifurcation and main bronchiPulmonary arteries and veinsHilar Lymph Nodelymphadenopathy due to metastases or primary tumor. Other causes includehiatial hernia,aortic aneurysm,Thyroid mass,duplication cyst, andbronchogenic cyst.
17 Mediastinal LesionsMiddle lesions – thoracic aortic aneurysms, hematomas, neoplasms, lymphadenopathy, esophageal lesions, and diaphragmatic hernias.Enlarged lymph nodes are the most frequent cause of a middle mediastinal mass.lymphadenopathyMass obscuring the right tracheal border - lymphadenopathyTrachea is located in the middle mediastinum, thus this lesion is also in the middle mediastinum.
25 Incidence 1 in 100000 Thrice more common than bronchial adenoma 1/3000 admission at large medical centreNeural commonest 20-27%Thymic second 19-26%Cyst third 18-21%Teratomas \ lymphoma fourth 12%Neural , Thymic, developmental ,Lymphoma :88% of all mediastinal tumours
26 Children Adult Neural tumours 40% Lymphoma 20% Teratomas & Cysts 10-15%Thymic rarePosterior MediastinumMost often benign2/3 of tumors symptomaticNeural tumours 20-27%Thymic 19-26%Cyst third 18-21%Teratoma \ lympho 11-12%Anterior MediastinumOften Malignant1/3 of tumors are symptomaticAges 30 – 50
27 Malignant Tumors Invasion Structure Tracheobronchial tree and lungsEsophagusSuperior Vena CavaPleura and Chest WallIntrathoracic nerves
32 Ganglioneuroblastoma Neuroblastoma GanglioneuromaGanglioneuroblastomaNeuroblastomaMost common< 20 yrs agePosterior mediastinumSex : equalEncapsulatedSlow growingBenign, May be malignantRare tumour in adults50% in first 3 yr of ageMajority occur in adrenal medullaEqual among both sexOften pear shaped or lobulatedMajority are encapsulatedMust be regarded as malignantAdults rarelyWithin 2 yrs ,Adrenal medulla, 20% in thoraxRetroperitonealEqual in both sexesRadio-logically less well definedHighly malignantLocally invasiveSpontaneous regression may occur
36 Thymic hyperplasia Nearly always infantile or childhood Usually asymptomaticPronounced in HIV, SLE,ThyrotoxicosisIndistinct from other thymic t0 on Radio or CTSteroids may reduceSubtotal surgery
37 Thymoma Epithelial neoplasms most common primary neoplasms of the anterior superior mediastinumAny age , rare <20, nearly all middle-aged adults.Male predominance½ of the patients are asymptomatic25-30% of patients have symptoms related to compression of adjacent mediastinal structures including cough, chest pain, and shortness of breath
38 Thymoma may have myasthenia gravis (30-40%), pure red cell aplasia, hypogammoglobulinemia,endocrine disorderscan be completely encapsulated (benign) or locally invasive without a fibrous capsuleclassified by predominant cell types:epithelial,lymphoid, orBiphasic , mixed or lymphoepithelial typeone- third of thymomas are invasive and may grow into the surrounding mediastinal structures,
39 ThymomaThis is determined at surgery and is not a histologic diagnosis,local invasion of the pleura occurs frequently,distant metastases are infrequentSurgical removal enmass with capsule intactMedian sterotomyThoracotomyTranscervical approachRadiotherapy usually reserved for incomplete excissionChemo-sensitive (May be) : cis, doxo, vin, c-phos
40 Encapsulated thymomaEncapsulated thymoma: 51 y/o asymptomatic male. PA chest radiograph demonstrates a mediastinal mass with smooth borders at the right paracardiac region causing effacement of the right heart border (positive silhouette sign). Contrast-enhanced chest CT (mediastinal window) demonstrates a heterogeneous, right-sided anterior mediastinal mass (*) abutting the right heart border.
47 Mediastinal Lymphoma Mediastinum is involved in 50% Hodgkin’s diseases Most cases are of nodular sclerosing typeTreatable and many are curable tooIntensive chemotherapy or radiotherapy or bothRadio alone relapse 50-74%Chemo alone relapse 33-50%“MOPP” or “DBVD” followed by radio preferred
52 Developmental Mediastinal cysts Congenital ; 16% of all mediastinal cystForegut duplication largest groupPleuropericardial next to it
53 Pleuropericardial cysts SynonymsPericardial cystCoelomic cystSpring water cystHydrocele of mediastinum1 / per year70% occur in right cardiophrenic angleUsually anteriorMale : Female 1 :1All ages5 – 25 cmsSoft , unilocularCrystal clear spring water , transudate with acellular & little proteinsAsymptomaticChest painRadiographSharply demarcaedRoundedSmooth edgedAnterior mass
56 Diagnostic of mediastinal masses Chest X-RaysCT ( Computed Tomography)/MRIMost valuable for diagnosisDone in most of casesCT guided needle biopsyMediastinoscopy / ant. mediastinotomyDefinite diagnosisMediastinoscopy/ant. medistinotomy with biopsyDefinite with establishing the disease diagnosisRadionuclide ScanningGoiterBarium studiesFor: hernia,diverticuli,achalasiaPercutaneous fine needle biopsyendoscopic ultra soundguided biopsyVideo assisted thoracoscopic removal of mass
61 Thoracoscopic biopsy (video-assisted thoracoscopy) Limited to inferior mediastinum.
62 Endoscopic Ultrasound: No incision, no anesthesia
63 Endoscopic ultrasound guided biopsy of mediastinal lesions has a major impact on patient management. It is a safe and sensitive minimally invasive method for evaluating patients with a solid lesion of the mediastinum suspected by CT scanning.It has a significant impact on patient management and should be considered for diagnosing the spread of cancer to the mediastinum in patients with lung cancer considered for surgery, as well as for the primary diagnosis of solid lesions located in the mediastinum adjacent to the oesophagus.Thorax 2002 Feb;57(2):98-103
64 “Endoscopic ultrasonography also provides information helpful for clinical staging of lung cancer and is the procedure of choice for performing fine-needle aspiration biopsy of posterior mediastinal and subcarinal lymph nodes.”AJCC manual 2007
65 CT scan or MRICT scan or MRI with contrast is always indicated for further evaluation.MRI is preferred for neurogenic lesions but obtaining a CT scan is never wrong with a mediastinal mass.CT-guided transthoracic fine needle aspiration (FNA): Limited by surrounding vascular structures, size of the targeted lesion.Pneumothorax risk.
66 Prognosis Varies depending on type of tumors and resection. Benign tumors – excellent prognosisMalignant tumors – depends on the type