title: Marked hyperprolactinemia in subclinical hypothyroidism.
abstract: Hyperprolactinemia is common in primary hypothyroidism but, to our knowledge, marked elevation of serum prolactin in subclinical hypothyroidism has not been previously reported. A 45-year-old woman presenting with carpal tunnel syndrome was found to have a minimally elevated level of thyrotropin with a normal level of thyroxine. Thyrotropin releasing hormone stimulation testing revealed hyperresponsiveness consistent with primary hypothyroidism. An unstimulated prolactin level was 187 micrograms/L and returned to normal with levothyroxine therapy. Results of visual field testing were normal, and a computed tomographic scan of the pituitary gland revealed no evidence of a macroadenoma. This case demonstrates the occurrence of significant hyperprolactinemia in the absence of overt primary hypothyroidism.
authors.affiliation: Department of Medicine, US Air Force Medical Center, Wright-Patterson Air Force Base, Ohio.
authors.forename: K E
authors.initials: KE
authors.lastname: Olive
authors.forename: J V
authors.initials: JV
authors.lastname: Hennessey
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000188:drug therapy / Q000209:etiology*; D007037:Hypothyroidism / Q000150:complications* / Q000175:diagnosis; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000627:therapeutic use
chemical_list: D013974:Thyroxine