THE MEDIASTINUM OBJECTIVES SURGICAL ANATOMY OF MEDIASTINUM MOST
THE MEDIASTINUM OBJECTIVES: SURGICAL ANATOMY OF MEDIASTINUM MOST COMMON MEDIASTINAL CYSTS MOST COMMON MEDIASTINAL TUMOURS AND MANAGMEDNT SUPERIOR VENA CAVA SYNDROME
ANATOMY The mediastinum is the space between the thoracic inlet and the diaphragm, the right and left pleural surfaces, the sternum and the vertebral column. It is subdivided into superior and inferior mediastinum by an arbitrary line extending from the manubriosternal angle to T 4/T 5 intervertebral space.
ANTERIOR OR ANTEROSUPERIOR: CONTAINS THE THYMUS, LYMPH NODES AND FAT. (FIG. 36). MIDDLE : CONTAINS THE HEART AND PERICARDIUM , SUPERIOR AND INFERIOR VENAE CAVAE , ASCENDING AORTA , AORTIC ARCH AND ITS BRANCHES , BRACHIOCEPHALIC VEIN , PULMONARY ARTERIES AND VEINS , PHRENIC AND VAGUS NERVES , TRACHEA AND MAIN BRONCHI , LYMPH NODES AND FAT. POSTERIOR: CONTAINS THE ESOPHAGUS, DESCENDING AORTA, AZYGOUS AND HEMIAZYGOUS VEINS, THORACIC DUCT, SYMPATHETIC CHAIN AND LYMPH NODES.
MEDIASTINAL MASSES . ANTEROSUPERIOR MEDIASTINUM 4 T THYMIC TUMOR OR CYST. RETROSTERNAL THYROID OR NEOPLASM. GERM-CELL TUMORS. LYMPHOMA.
Middle mediastinum Lymphadenopathy. Vascular: Aortic aneurysm, anomalies of great vessels. Pericardial cyst or diverticulum. Bronchogenic cyst. Tracheal tumors.
. Posterior mediastinum Neurogenic tumors ( benign and malignant) : Peripheral intercostal nerves (neurofibroma, neurilemmoma, neurofibrosarcoma). Sympathetic ganglia (ganglioneuroma, neuroblastoma). Paraganglia (phaeochromocytoma, paraganglioma). Meningocele. Esophageal Hiatus tumors, diverticulae, duplication cysts. hernia. Thoracic duct cysts, cystic hygroma (lymphangioma). Extramedullary hematopoesis
MEDIASTIAL ANTERIOR MIDDLE CYSTS: MEDIASTINUM: POSTERIOR MEDIASTINUM:
Clinical Picture: Half of patients are asymptomatic with normal physical examination. Symptomatic lesions and lesions in children are more likely to be malignant. 1. Symptoms Local: Pain (chest or back), dyspnea, cough, dysphagia, … Systemic: Fever, malaise, weight loss, night sweats, … 2. Signs Local: Cervical lymphadenopathy, facial and/or arm swelling, tracheal deviation. General: Testicular masses, hepatosplenomegaly, muscle weakness.
Investigations : 1. Laboratory Complete blood picture: Anemia, leucocytosis, thrombocytopenia. Lactate dehydrogenase: Elevated in lymphomas, seminomas. ß-human chorionic gonadotrophin: May be increased in seminomas. α-fetoprotein : αIndicates a non-seminoma germ-cell tumor. It is normal in pure seminoma. Alkaline phosphatase and calcium: Altered with parathyroid tumors. Urine metanephrines: Vanilyl mandelic acid increased in phaeochromocytoma.
. Radiological CXR. CT scan with IV contrast. MRI for neurogenic and vascular lesions. Angiography for vascular lesions. Barium swallow for posterior mediastinal masses. Radionuclide scintigraphy for thyroid or parathyroid masses. Gallium scan in lymphoma
. Biopsy Fine-needle aspiration biopsy. Core-tissue biopsy. Mediastinoscopy. Anterior mediastinotomy. Video-assisted thoracoscopic surgery (VATS). Bronchoscopy and trans-bronchial lung biopsy. Esophagoscopy.
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