Document Type


Publication Date



School of Medicine


Otolaryngology, Head and Neck Surgery


Background. Undifferentiated anaplastic carcinoma rarely develops from chronic hyperthyroidism. Although acute hyperthy- roidism can develop prior to anaplastic transformation, chronic hyperthyroidism was thought to be a protective measure against thyroid malignancy. Methods. A 79-year-old female presented acutely to the hospital with dyspnea. She had been taking methimazole for chronic hyperthyroidism due to toxic thyroid nodules, previously biopsied as benign. Upon admission, imaging showed tracheal compression, requiring a total thyroidectomy with tracheostomy for airway management. Results. Pathology demonstrated undifferentiated anaplastic thyroid carcinoma. The patient passed away shortly after hospital discharge. Despite treatment with methimazole for many years, abrupt enlargement of her toxic multinodular goiter was consistent with malignant transformation. Chronic hyperthyroidism and toxic nodules are rarely associated with thyroid malignancy, with only one previous report documenting association with anaplastic thyroid carcinoma. Conclusion. Progressive thyroid enlargement and acute worsening of previously controlled hyperthyroidism should promote concern for disease regardless of baseline thyroid function.

Source Citation

Zalzal, H. G., Chung, J., & Perini, J. A. (2018). Remarkable Presentation: Anaplastic Thyroid Carcinoma Arising from Chronic Hyperthyroidism. Case Reports in Endocrinology, 2018, 1–4.


Copyright © 2018 Habib G. Zalzal et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.



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