title: Hemorrhage into a thyroid nodule as a cause of thyrotoxicosis.
abstract: OBJECTIVE
  To describe a case of thyrotoxicosis after nontraumatic hemorrhage into the thyroid gland during anticoagulant therapy.
  
  
  METHODS
  We report the details of the initial presentation, subsequent course, and outcome in a patient with a nontraumatic thyroid hematoma and thyrotoxicosis.
  
  
  RESULTS
  In a 63-year-old woman, an acute painful neck mass developed during follow-up while she was receiving low-molecular-weight heparin therapy for deep vein thrombosis. Ultrasound study and magnetic resonance imaging revealed a massive intrathyroidal hematoma. This finding was followed by an increase in serum free thyroxine and free triiodothyronine levels and a decrease in the level of serum thyroid-stimulating hormone (thyrotropin). Anticoagulant therapy was discontinued. The clinical course of the thyrotoxicosis was self-limited, and no antithyroid therapy was necessary. The serum thyroid hormone levels decreased into normal ranges as the hematoma underwent subtotal shrinkage.
  
  
  CONCLUSIONS
  Endocrine glands are highly vascularized tissues, but nontraumatic hematomas into these organs are extremely rare conditions. Nevertheless, physicians should be aware of the potential occurrence of such a situation, as emphasized in the current case report.
authors.affiliation: Department of Internal Medicine, Hacettepe University Medical School, Hamamönü Sihhiye, Ankara, Turkey.
authors.forename: Ibrahim Koral
authors.initials: IK
authors.lastname: Onal
authors.forename: Selçuk
authors.initials: S
authors.lastname: Dağdelen
authors.forename: Ayşegül
authors.initials: A
authors.lastname: Atmaca
authors.forename: Omer
authors.initials: O
authors.lastname: Karadağ
authors.forename: Nezaket
authors.initials: N
authors.lastname: Adalar
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D048909:Diabetes Complications / Q000188:drug therapy; D005260:Female; D006406:Hematoma / Q000139:chemically induced; D006470:Hemorrhage / Q000139:chemically induced / Q000150:complications*; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D013960:Thyroid Function Tests; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000473:pathology*; D013971:Thyrotoxicosis / Q000188:drug therapy / Q000209:etiology*; D018615:Ultrasonography, Doppler, Color
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight