title: Choriocarcinoma presenting with thyrotoxicosis.
abstract: We describe a 26-year-old man with metastatic choriocarcinoma who presented with hyperthyroidism associated with elevated β-human chorionic gonadotropin (B-HCG) and respiratory failure secondary to diffuse lung metastasis. After the first cycle of chemotherapy, the concentration of B-HCG dramatically decreased and the patient became euthyroid, allowing us to discontinue antithyroid medications. The patient's hyperthyroidism was caused by stimulation of the thyroid gland by high B-HCG levels, as shown by the marked improvement of the patient's thyroid function panel after chemotherapy.
authors.affiliation: Department of Internal Medicine (Sotello, Rivas), Division of Pulmonary/Critical Care Medicine (Test), and Division of Endocrinology (Lado-Abeal), Texas Tech University Health Science Center, Lubbock, Texas.
authors.forename: David
authors.initials: D
authors.lastname: Sotello
authors.affiliation: Department of Internal Medicine (Sotello, Rivas), Division of Pulmonary/Critical Care Medicine (Test), and Division of Endocrinology (Lado-Abeal), Texas Tech University Health Science Center, Lubbock, Texas.
authors.forename: Ana Marcella
authors.initials: AM
authors.lastname: Rivas
authors.affiliation: Department of Internal Medicine (Sotello, Rivas), Division of Pulmonary/Critical Care Medicine (Test), and Division of Endocrinology (Lado-Abeal), Texas Tech University Health Science Center, Lubbock, Texas.
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Test
authors.affiliation: Department of Internal Medicine (Sotello, Rivas), Division of Pulmonary/Critical Care Medicine (Test), and Division of Endocrinology (Lado-Abeal), Texas Tech University Health Science Center, Lubbock, Texas.
authors.forename: Joaquin
authors.initials: J
authors.lastname: Lado-Abeal