Thyroid Neoplasms

A 42-year-old woman from Mumbai presents with a 2-month history of a painless, firm nodule in the lower pole of the right thyroid lobe. She denies dysphagia, dyspnea, or voice changes. Physical examination reveals a solitary 1.5 cm nodule with no cervical lymphadenopathy. TSH is normal. Fine-needle aspiration cytology (FNAC) shows follicular cells arranged in a microfollicular pattern with increased mitotic activity and focal areas of capsular invasion. Which of the following is the most likely diagnosis?

A 50-year-old man undergoes total thyroidectomy for papillary thyroid carcinoma (PTC). Histopathology confirms PTC with vascular invasion and extrathyroidal extension. Six weeks post-operatively, serum thyroglobulin (Tg) is elevated at 8 ng/mL (normal <0.5 ng/mL) despite TSH suppression. Which is the most appropriate next investigation to detect metastatic disease?

Regarding papillary thyroid carcinoma (PTC), all of the following statements are true EXCEPT:

A 38-year-old man from Mumbai undergoes total thyroidectomy for a 3 cm papillary thyroid carcinoma (PTC) with no extrathyroidal extension or lymph node involvement (Stage I). Histology confirms classical variant PTC. Postoperative TSH is 2.5 mIU/L. What is the most appropriate next step in management?

Which thyroid neoplasm is characterized by the presence of Orphan Annie eye nuclei and follicular architecture with minimal nuclear pleomorphism?