This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
[{'content': 'There was a sudden increases in the size of Thyroid swelling along with pain. Most likely cause is \nSelect and explain. \nA. Hemorrhage within the cyst, B. Malignant change, C. Nodular goiter, D. Colloid goiter', 'role': 'user'}, {'content': 'Answer: A \nExplanation: . A painful nodule, sudden appearance, or rapid enlargement of a nodule raises suspicion of carcinoma but is usually due to haemorrhage into a simple nodule. Comment : more common among the given options is haemorrhage. other points to consider: Pain is not a common feature of thyroid swellings. Thyroiditis can present with a painful gland. Anaplastic carcinoma can cause local pain and pain referred to the ear if it infiltrates surrounding structures Source : Bailey and love 26 th edition Pg : 748', 'role': 'assistant'}]