A 40 year old female presenting with a slow growing painless mass is recently diagnosed to have thyroid cancer. Which is the most common subtype of thyroid cancer?

Papillary carcinoma accounts for 80% of all thyroid malignancies in iodine sufficient areas and is the predominant thyroid cancer in children and individuals exposed to external radiation. It is more common in women with a 2:1 female to male ratio. Mean age of presentation is 30 to 40 years. Most patients presents with a slow growing painless mass in the neck. In locally advanced invasive disease patients presents with dysphagia, dyspnea and dysphonia. It is usually diagnosed by FNAB of the thyroid mass or lymph node. Pathologic diagnosis is made by the characteristic nuclear features such as presence of cuboidal cells with pale, abundant cytoplasm, crowded nuclei that may demonstrate grooving and presence of intranuclear cytoplasmic inclusions (Orphan Annie nuclei). Psammoma bodies may also be present. Ref: Schwaz's Principles of Surgery, 9e, chapter 38