Please cite this article in press as: Zantour B, et al. Hashimoto’s thyroiditis and severe hypothyroidism, associated with a single hot nodule. Rev Esp Med Nucl. 2011. doi:10.1016/j.remn.2010.10.011 ARTICLE IN PRESS G Model REMN-230; No. of Pages 3 Rev Esp Med Nucl. 2011;xxx(xx):xxx–xxx Clinical note Hashimoto’s thyroiditis and severe hypothyroidism, associated with a single hot nodule B. Zantour a,* , M.H. Sfar a , W. Alaya a , W. Chebbi a , K. Chatti b , and S. Jerbi c a Department of Endocrinology and Internal Medicine, Tahar Sfar Hospital, Hiboune, Mahdia, Tunisia b Department of Nuclear Medicine, Sahloul Hospital, Sousse, Tunisia c Department of Radiology, Tahar Sfar Hospital, Hiboune, Mahdia, Tunisia article info Article history: Received 2 September 2010 Accepted 20 October 2010 Available online xxx Keywords: Hashimoto’s thyroiditis Hypothyroidism Hot nodule Thyroid scintigraphy abstract We report the case of a 27 year-old man with symptoms of severe hypothyroidism that have evolved since his adolescence. He was found to have an 11 mm right lobe thyroid nodule. On thyroid ultrasound, the nodule was solid, heterogeneous with markedly atrophic hypoechoic surrounding tissue. Thyroid scintigraphy revealed increased 99m Tc pertechnetate and 131 I uptake, with persistence of 131 I hyper- fixation after 24 h. There was no fixation of the radiotracer in the remaining tissue. Thyroid function tests found TSH > 100 mIU/l, free thyroxine level 0.9 pmol/l (normal values 11.5-21.8), anti-thyroid per- oxydase antibodies strongly positive > 1,000 IU/ml, and anti-thyroglobulin antibodies negative. One year after levothyroxine therapy, the nodule decreased to 40% of its original size. Hashimoto’s thyroiditis may present as a single hot nodule and severe hypothyroidism. Data of reported cases suggest that the hot nodule corresponds to a localized hyperplasia of the less diseased portions of the thyroid. Chronic stimulation by TSH may have promoted nodular growth and isotopes uptake. © 2010 Elsevier España, S.L. and SEMNIM. All rights reserved. Tiroiditis de Hashimoto e hipotiroidismo severo, asociado con un solo nódulo caliente Palabras clave: Tiroiditis de Hashimoto Hipotiroidismo Nódulo caliente Gammagrafía tiroidea resumen Se presenta el caso de un hombre de 27 a ˜ nos de edad con síntomas de hipotiroidismo severo en evolución desde la adolescencia, y un nódulo tiroideo de 11 mm en el lóbulo derecho. En la ecografía del tiroides, el nódulo era sólido, heterogéneo y con un tejido notablemente atrófico hipoecoico alrededor. La gam- magrafía tiroidea reveló un aumento en la captación en el nódulo tanto del 99m Tc-pertecnetato como del 131 I, con persistencia de la captación de 131 I en la imagen de 24 h. No se observó fijación del radiotrazador en el resto de la glándula. Los análisis mostraron unos niveles séricos de TSH > 100 mUI/l, tiroxina libre 0,9 pmol/l (11,5-21,8), anticuerpos antitiroperoxidasa positivo > 1.000 UI/ml y anticuerpos antitiroglob- ulina negativos. Un a ˜ no después del tratamiento con levotiroxina, el nódulo redujo en un 40% su tama ˜ no original. La tiroiditis de Hashimoto puede presentarse como un solo nódulo caliente e hipotiroidismo severo. Datos reportados sugieren que el nódulo caliente corresponde a una hiperplasia localizada de las por- ciones menos da ˜ nadas del tiroides. La estimulación crónica por TSH puede haber favorecido el crecimiento nodular y la captación de los isótopos. © 2010 Elsevier Espa ˜ na, S.L. and SEMNIM. Todos los derechos reservados. Introduction Hashimoto’s thyroiditis (HT) is a chronic thyroid disorder char- acterized by autoimmune destruction of the thyroid, resulting in lymphocyte infiltration, goiter, and eventually hypothyroidism. In children and adolescents, it’s the most common thyropathy and is the main cause of goiter. 1 Hypothyroidism is the result of severe fibrous destruction at an advanced stage of the disease. 1 The scintigraphic findings of HT are highly variable and can mimic several thyroid disorders including diffuse hyperplasia, nodular goiter, cold nodules, and rarely hot nodules. 2 Association of * Corresponding author. E-mail address: bahazantour@yahoo.fr (B. Zantour). solitary hot nodule with hypothyroidism is a rare condition, it has been previously reported in few cases, all female, 28 to 60 years old. 3–6 Herein, we report a male patient presenting with severe hypothyroidism evolving since adolescence, associated to a single hot pertechnetate and iodine 131 thyroid nodule. Case report A 27-year-old man was referred to our endocrinology unit for short stature, decreased skin pilosity, pallor and asthenia. He was living in an area of iodine sufficiency. His mother had primary hypothyroidism treated by Levothyroxine since 15 years. He was born at term of a normal pregnancy. He had a normal psychomotor development. He went to school for 9 years and was unable to finish 0212-6982/$ – see front matter © 2010 Elsevier España, S.L. and SEMNIM. All rights reserved. doi:10.1016/j.remn.2010.10.011