Elevated TSH and hypothyroid by thyroid function tests Macroadenoma • Formal visual field test, • Neurosurgical consultation, • Discuss risks with pregnancy • Expectant management • Repeat MRI in 6–12 months Normal Repeat TSH Normal scan or hyperplasia Microadenoma Discuss risks with pregnancy • Repeat prolactin and  TSH in 6 to 12 weeks • Document resolution • Amenorrhea • Progestin challenge Regular periods or Progestin challenge every 3 months Medical management Bromocriptine • Insure periods Resume or replace • Coned-down view may be   appropriate in certain   situations. • In cases of clear   drug-induced   hyperprolactinemia, a scan   may not be required.
Micro or Macroadenoma • Prolactin remains  elevated or recurs • CNS symptoms persist or recur Microadenoma • Decreased prolactin • Absent CNS signs or symptoms Macroadenoma • Prolactin levels and CNS   symptoms return to normal No further scans required unless CNS signs or symptoms develop or prolactin level increases Initially scan at 6 months 1–4 years thereafter Neurosurgery
Figure 31.9 Workup for hyperprolactinemia. TSH, thyroid-stimulating hormone; MRI, magnetic resonance imaging; CT, computed tomography; HRT, hormone replacement therapy; OCPs, oral contraceptive pills; CNS, central nervous system.
Figure 31.10 Prolactin levels in 235 patients with galactorrhea. Among patients with a tumor, open triangles denote associated acromegaly, and solid circles and solid triangles denote previous radiotherapy or surgical resection, respectively. (From Kleinberg DL, Noel GL, Frantz AG. Galactorrhea: a study of 235 cases, including 48 with pituitary tumors. N Engl J Med 1977;296:589–600, with permission.) in that group, approximately one-third will have a pituitary adenoma (282). In anovulatory women, 3% to 10% of women diagnosed with polycystic ovary disease have coexistent and usually modest hyperprolactinemia (283,284) (Fig. 31.10).
Prolactin and TSH levels should be measured in all patients with delayed puberty. Pituitary abnormalities, including craniopharyngiomas and adenomas, should be considered in all cases of delayed puberty accompanied by low levels of gonadotropins, regardless of whether prolactin levels are elevated. When prolactin-secreting pituitary adenomas are present, the condition of multiple endocrine neoplasia type 1 (MEN-1) syndrome (gastrinomas, insulinoma, parathyroid hyperplasia, and pituitary neoplasia) should be considered, although symptoms of pituitary adenoma are rarely the presenting symptom. Patients who have a pituitary adenoma and a family history of multiple adenomas warrant special attention (285). Prolactinomas are noted in approximately 20% of patients with MEN-1. The MEN-1 gene is localized to chromosome 11q13 and appears to act as a constitutive tumor suppressor gene. An inactivating mutation results in development of the tumor. It is thought that prolactin-secreting pituitary adenomas that occur in patients with MEN-1 may be more aggressive than sporadic cases (286).