title: Pendulum swings from hypo- to hyperthyroidism: thyrotoxicosis after severe hypothyroidism following neck irradiation in a patient with a history of Hodgkin's lymphoma.
abstract: BACKGROUND
  A change in a thyrometabolic state from severe hypothyroidism to thyrotoxicosis is very uncommon, but possible in some circumstances.
  
  
  METHODS
  A 27-year old female presented with clinical and biochemical thyrotoxicosis with a previous history chemo- and radiotherapy (including the neck region) for a Hodgkin's lymphoma (at the age of 18). At the age of 20 this was followed by severe hypothyrodism [TSH > 100 μIU/mL (reference range: 0.27-4.2)]. She was stated on L-thyroxine, but the dose was later reduced and subsequently discontinued. She had significantly elevated titres of both anti-thyroid peroxidase antibodies and anti-TSH-receptor antibodies throughout the course of disease. Thyroid scintigraphy revealed a normal and homogenous iodine uptake.
  
  
  CONCLUSIONS
  We suspect that a gradual switch from thyroid-blocking to thyroid-stimulating antibodies resulted in development of an overt thyrotoxicosis, possibly with a contributory effect of neck irradiation on her autoimmune status.
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland ; Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, Lodz, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Lewandowski
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dąbrowska
authors.affiliation: Department of Nuclear Medicine and Oncological Endocrinology, Zgierz District Hospital, Zgierz, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Makarewicz
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland ; Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, Lodz, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Lewiński
keywords: Graves’ disease; Neck irradiation; Thyroid antibodies; Thyrotoxicosis