<prompt> Which of the following statements is true regarding retrosternal goiters?Operated only if patient is symptomaticSternal incision is always requiredMajority of the giotres derive their blood supply from mediastinal vesselsMajority of the retrosternal giotres can be removed by a neck incision  <response>: Retrosternal goiter substernal goiter Mediastinal goiter Majority95 of the retrosternal goitres can be removed by a neck incision If 50 of thyroid tissue is located below the opening of thoracic cage MC symptom - Dyspnea Dysphagia Hoarseness of voice Dilated veins over Anterior chest wall. PEMBEON sign- positive If bilateral upper limb elevated above forehead, facial puffiness and facial congestion seen 