This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: Surgery
[{'content': 'A biopsy from a mass in front of the neck revealed parafollicular cells. How do you follow up? \nSelect and explain. \nA. Calcitonin, B. T4, C. Thyroxine, D. Thyroglobulin', 'role': 'user'}, {'content': "Answer: A \nExplanation: Biopsy from the mass in front of the neck revealed parafollicular cells indicating that it's a case of Medullary carcinoma of the thyroid. Medullary carcinoma of the thyroid (MTC): It is a distinct thyroid carcinoma that originates in the parafollicular C cells of the thyroid gland. These C cells produce calcitonin. Hence it is used for follow up of these patients", 'role': 'assistant'}]