<prompt> A 50 year old male comes with co easy fatiguability, dyspnea neck swelling. On examination, he demonstrates the following sign. What is the appropriate of this condition?Surgery transthoracic approachRadioactive iodine ablationSurgery transcervical approachLevothyroxine to suppress TSH  <response>: Retrosternal goitre SubsternalMediastinalIntrathoracic If 50 of thyroid tissue is located below the opening of thoracic cage. Most patients are asymptomatic Diagnosed incidentally on radiological investigations Signs Symptoms- MC symptom - Dyspnea due to compression of trachea, in night- Dysphagia due to compression of esophagus- Hoarseness of voice due to compression of Recurrent laryngeal nerve- Dilated veins over Anterior chest wall.- PEMBEON sign- positive If bilateral upper limb elevated above forehead, facial puffiness and facialcongestion seen Treatment- Thyroidectomy by cervical incision Thyroidectomy is indicated for retrosternal goitre for patients with clinical symptoms stridor or dysphagia andor radiological evidence of significant tracheal narrowing, oesophageal compression or SVC syndrome. - Radioisotopes used T12 of I 123 - 13 hours shoer fall life - so used for diagnostic purposes RAI SCAN T12 of I 131 - 8 days Longer half-life - so used for therapeutic purposes RAI ABLATION. Radio Active Iodine Ablation- I131 emits beta- rays 90 and gamma- rays 10- Beta rays are responsible for Therapeutic effects ablation- Depth of penetration of beta rays - 0.5 mm Ablates only thyroid, even parathyroid are safe- Gamma rays are responsible for side effects- Gamma rays are used in Tracer studies - Gamma probe can be used for identifying the area that emits gamma rays. So, useful in Radioactive Iodine scan - Absolute contraindication of RAI Ablation because gamma rays are emitted Pregnancy Lactation 