title: [31-year-old male patient with testicular mass and hyperthyroidism].
abstract: An excess of human chorionic gonadotropin (hCG) is a rare differential diagnosis of hyperthyroidism, due to the TSH-like effect of hCG. hCG levels physiologically increase during pregnancy. In patients with germ cell tumors of the testicles and the ovary, a pathological increase of hCG serum concentrations may also be found, depending on the histological subtype. We report on a 31-year-old male patient with overt clinical hyperthyroidism resulting of a hCG-producing metastasized germ cell tumor of the right testicle. After initiation of chemotherapy, thyroid function normalized in parallel to the tumor's remission with marked decrease of hCG levels.
authors.affiliation: Abteilung für Endokrinologie, Diabetes, Angiologie, Nephrologie und Klinische Chemie, Medizinische Universitätsklinik Tübingen.
authors.forename: B
authors.initials: B
authors.lastname: Besemer
authors.forename: K
authors.initials: K
authors.lastname: Mann
authors.forename: M
authors.initials: M
authors.lastname: Horger
authors.forename: K
authors.initials: K
authors.lastname: Müssig
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications* / Q000175:diagnosis*; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis* / Q000556:secondary*; D013736:Testicular Neoplasms / Q000175:diagnosis* / Q000209:etiology*; D013964:Thyroid Neoplasms / Q000150:complications* / Q000175:diagnosis*