A 78-year-old woman presents with a 2-month history of rapidly enlarging neck mass, progressive dysphagia, and hoarseness. Vital signs show BP 138/82, HR 92, RR 18, temp 37.2°C, SpO2 98%. She denies recent weight loss. CT imaging demonstrates an invasive thyroid tumor with local compression of the trachea and esophagus. TSH is elevated at 8.2 mIU/L. Biopsy reveals highly pleomorphic undifferentiated giant cells. Which diagnosis is most likely?

1. A)Papillary thyroid carcinoma
2. B)Medullary thyroid carcinoma
3. C)Follicular thyroid adenoma
4. D)Hashimoto thyroiditis
5. E)Anaplastic thyroid carcinomaGABARITO