Surgery Which of the following is not true about medullary thyroid carcinoma? A Are a type of neuroendocrine tumors B Associated with MEN 2A and 2B syndrome C Form about 25% of the thyroid malignancies D Tumor cells may secrete serotonin, ACTH and VIP 💡 Explanation Which of the following is not true about medullary thyroid carcinoma? ✓ Correct Answer: C. Form about 25% of the thyroid malignancies