title: Description of the thyroid hormone resistance syndrome illustrated by such a case, which had two different carcinomas and was mistreated with iodine-131.
abstract: OBJECTIVE
  Hyperthyroidism with increased serum thyroid hormones and also increased thyroid stimulating hormone (TSH) is described as the resistance thyroid hormone (RTH) syndrome. This syndrome may be due to various factors including tumors. We describe the different types of RTH syndrome and mention that this syndrome may be misdiagnosed and mistreated. To illustrate the RTH syndrome we describe such a case which also had two different carcinomas. This case was treated with anti-thyroid drugs, triiodothyroacetic acid and iodine-131 (¹³¹I). In the following 5.5 years after ¹³¹I treatment, TSH progressively increased and was not suppressed by normal doses of L-thyroxine (L-T4). A thyroid nodule was diagnosed as papillary thyroid carcinoma (PTC) and a small cell neuroendocrine carcinoma was diagnosed in the nasal septum. Under L-T4 replacement treatment and after ablation of both carcinomas, TSH returned to normal. Small cell neuroendocrine carcinomas accompanied with PTC, are extremely rare causes of RTH.
  
  
  CONCLUSIONS
  A description of the resistance to thyroid hormone syndrome is presented and this syndrome is illustrated by a referring case which could be of a selective pituitary type or due to the neuroendocrine tumor.
authors.affiliation: Department of Nuclear Medicine, First Affiliated Hospital of the Xi'an Jiaotong, University School of Medicine, 277#, Yanta West Road, Xi'an, Shaanxi Province, China. yangaimin@mail.xjtu.edu.cn.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Xue
authors.forename: Xi
authors.initials: X
authors.lastname: Jia
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.forename: Fenru
authors.initials: F
authors.lastname: Zhang
authors.forename: Aimin
authors.initials: A
authors.lastname: Yang
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D009378:Neoplasms, Multiple Primary / Q000150:complications / Q000175:diagnosis* / Q000532:radiotherapy*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D018382:Thyroid Hormone Resistance Syndrome / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D013964:Thyroid Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000532:radiotherapy*; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals