Thyroid Neoplasms

Medullary thyroid carcinoma is associated with mutations in which proto-oncogene, and what is the biochemical marker used for diagnosis and surveillance?

A 45-year-old woman undergoes thyroidectomy for a thyroid nodule. Histopathology shows a malignant tumour with follicular architecture, moderate nuclear pleomorphism, and scattered mitotic figures. What is the most common type of thyroid cancer in this patient?

A 52-year-old man with a history of medullary thyroid carcinoma undergoes genetic testing and is found to have a RET proto-oncogene mutation. Which of the following is the most common site of metastasis in medullary thyroid carcinoma?

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?

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