Development of subclinical hyperthyroidism due to Graves' disease in a hypothyroid woman who had undergone hemithyroidectomy for adenomatous goiter and radiotherapy for nasopharyngeal cancer.
A variety of thyroid disorders develop following external radiation to head and neck cancers. Hypothyroidism is the most common clinical consequence of the radiotherapy and lifelong thyroid hormone replacement is required in many cases. Patients who received both hemithyroidectomy and the external radiation to the neck are at especially high risk for permanent hypothyroidism. Here we report an unusual case with radiation-induced hypothyroidism who had undergone hemithyroidectomy for adenomatous goiter 8 years before the radiotherapy for nasopharyngeal cancer and subclinical hyperthyroidism due to Graves' disease developed during thyroxine replacement therapy. Thus subclinical hyperthyroidism due to Graves' disease can develop in patients with radiation-induced hypothyroidism even if they have undergone hemithyroidectomy for thyroid nodules. Therefore careful and periodic evaluation of thyroid function is required even on adequate thyroxine replacement therapy.
Nakagawa
Yoshinori
Y
Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
Mori
Kouki
K
Hoshikawa
Saeko
S
Ozaki
Hiroshi
H
Ito
Sadayoshi
S
Yoshida
Katsumi
K
D000328:Adult; D002277:Carcinoma / Q000532:radiotherapy*; D005260:Female; D006044:Goiter, Nodular / Q000601:surgery*; D006111:Graves Disease / Q000150:complications / Q000188:drug therapy* / Q000601:surgery; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D006801:Humans; D006980:Hyperthyroidism / Q000209:etiology* / Q000473:pathology; D007037:Hypothyroidism / Q000188:drug therapy / Q000209:etiology*; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries; D013965:Thyroidectomy / Q000009:adverse effects*; D013974:Thyroxine / Q000009:adverse effects / Q000627:therapeutic use
D013974:Thyroxine