Stable thyroid cancer in a patient with thoracic aortic aneurysm and MYH11 variation.

Summary: We report the case of a male patient with papillary thyroid cancer, familial thoracic aortic aneurysm and dissection, and a variation in the MYH11 gene. Because of considerable tumor bulk in the neck that was not resectable, the patient underwent partial resection at age 14 years. Since then, the patient has received only suppressive thyroid hormone therapy. He is now 71 years old, which is 57 years after the initial resection. The patient received care at our institution from July 2009 to August 2019, during which we documented the stability of multiple calcified masses in the neck. Follow-up examinations at another institution from September 2019 to April 2023 also confirmed the stability of the masses. The underlying cause of this unusually long indolent course of the disease is unclear. Whether extensive tumor calcifications or the MYH11 sequence variation contributed to the disease course is also uncertain. Learning points: Papillary thyroid cancer with neck metastases may, in some cases, be stable and remain asymptomatic for decades. If locoregional stability of papillary thyroid cancer is documented for many years, observation may be preferable to extensive neck surgery in selected cases. This is the first report of an MYH11 gene alteration and thoracic aortic aneurysm in a patient with papillary thyroid cancer with indolent neck metastases. Future studies of MYH11 gene alterations in thyroid carcinoma are needed.