All of the following are features of medullary carcinoma of thyroid, except:
High-Yield Explanation
Activating point mutations in RET proto-oncogene is associated with both familial & sporadic medullary carcinomas. RAS gene mutation is associated with follicular cancer of thyroid. Hence, option-3 is wrong Medullary thyroid carcinoma Neuroendocrine neoplasms derived from parafollicular cells, or C cells. Medullary carcinoma cells similar to normal C cells, secrete calcitonin. Hence, measurement of calcitonin levels plays impoant role in diagnosis & postoperative follow-up of patients. Cases associated with MEN types 2A or 2B, tumor can occur in younger patients & may even arise during first decade of life. MEN-2A Medullary thyroid carcinoma Pheochromocytoma Parathyroid adenoma MEN-2B Medullary thyroid carcinoma Pheochromocytoma Marfanoid habitus Mucosal neuromas