This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Thoracic extension of cervical goitre is usually approached through: \nSelect and explain. \nA. Neck, B. Chest, C. Combined cervico-thoracic route, D. Thoracoscopic', 'role': 'user'}, {'content': 'Answer: A \nExplanation: "Virtually all Intrathoracic goiters can be removed via a cervical incision." - Schwartz Sx\n\nA thoracic approach (median sternotomy) may be needed in the following cases\npatients with primary mediastinal goiters with no thyroid tissue in the neck.\npatient with previous thyroid operations who may have developed parasitic, mediastinal vessels.\npatients with invasive thyroid cancers for their complete removal or\nto control mediastinal bleeding during the operation.\n\nAlso know.\n\nA goiter is said to be mediastinal if at least 50% of thyroid tissue is located intrathoracically.\nMediastinal goiters can be\n\nPrimary\n\nconstitute only 1% of all mediastinal goiters\n\tarise from ectopic thyroid tissue.\ndo not have any connection with the thyroid tissue in the neck.\n\tderives its blood supply from the mediastinum.\n\nSecondary Mediastinal \n\narise from downward extension of cervical thyroid tissue.\nderive their blood supply from the thyroid vessels of neck.', 'role': 'assistant'}]