AAO-HNSF Primary Care Otolaryngology Handbook

THYROID CANCER

affect survival rates. Histologically, they have clear nuclei (“Orphan Annie” cells ) and may have psammoma bodies. Factors predictive of a better prognosis include small size (less than 1.5 centimeters [cm]) and absence of thyroid gland capsule involvement. For unknown reasons, this disease follows a much more indolent course when discovered in people under age 40. However, while papillary carcinoma patients under 40 years of age ultimately live longer, they also experience a higher rate of recurrence. Treatment of papillary carcinoma is somewhat controversial, and the pendulum has swung back and forth over the years. New guidelines from the American Thyroid Association published in 2015 recommend thyroid lobectomy for tumors less than 1 cm and without evidence of extrathy- roidal extension or lymphadenopathy. 1 For tumors 1–4 cm and without extrathyroidal extension or lymphadenopathy, thyroid lobectomy or total thyroidectomy is appropriate, depending on patient preference, presence of ultrasonographic abnormalities in the contralateral lobe, or need for radioiodine therapy. For patients with tumors greater than 4 cm, extrathy- roidal extension, cervical metastases, or a history of childhood head and neck radiation, a total thyroidectomy is recommended. As mentioned earlier, if cervical metastatic thyroid cancer is present, a modified or selective neck dissection is indicated, depending on the location of the disease. The greatest risks of thyroid surgery are hypo- parathyroidism secondary to injury or removal of the parathyroid glands, and recurrent laryngeal nerve injury, which may result in hoarse- ness, shortness of breath, and reduced exercise tolerance. Assessment of the patient’s baseline voice quality must be made preoperatively first. Examination of the larynx is recommended to assess vocal fold mobility in patients with preoperative complaints of dysphonia or an impaired voice. Even if patients have normal voice quality, assessment of the larynx is recommended if they have thyroid cancer with suspected extrathyroidal extension and/or prior neck surgery that increased the risk of laryngeal nerve injury, such as a carotid endarterectomy or cervical fusion surgery. Postoperative reassessment for a possible change in the voice should be made between two weeks and two months following thyroid surgery. 1 Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma. American Thyroid Association Guidelines Task Force on Medullary Thyroid Carcinoma: Wells, S.A. Jr., S.L. Asa, H. Dralle, R. Elisei, D.B. Evans, R.F. Gagel, N. Lee, A. Machens, J.F. Moley, F. Pacini, F. Raue, K. Frank-Raue, B. Robinson, M.S. Rosenthal, M. Santoro, M. Schlumberger, M. Shah, and S.G. Waguespack. 2015. Thyroid 25 (6): 567–610. doi: 10.1089/thy.2014.0335. Review. PMID: 25810047.

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