Prolactin-secreting adenoma

Anterior pituitary Pituitary prolactin-secreting adenoma Hypothyroidism Med ications—antipsychotics, verapamiI T Prolactin suppresses HPO axis TRH causing T prolactin, other abnormalities T Prolactin suppresses HPO axis... 

Israel JM, Jaquet P, Vincent JD (1985) The electrical properties of isolated human prolactin-secreting adenoma cells and their modification by dopamine. Endocrinology 777 1448-1455. 

The most common secretory neoplasm of the anterior pituitary gland is a prolactin-secreting adenoma (prolactinoma). An early symptom of prolactin excess is a milky discharge from the breasts. Because hyperprolactinemia may suppress the secretion of gonadotropic hormones (e.g., LH, FSH), menstrual irregularity, amenorrhea, and infertility may occur in women. In men, gonadotropic hormone dysfunction may lead to reduced libido, sexual impotence, and infertility. 

The hypothalamic factors which control anterior pituitary hormone secretion are shown in Figure I. Tumours secreting each of the anterior pituitary hormones have been identified. T.SH and gonadotrophin secreting tumours are rare. Gil and ACTH secreting tumours arc more common. Prolactin secreting adenomas (prolactinomas) arc the most common. 

Fedele, M DeMartino, I., Pivonello, R., et al. (2007) SOM230, a new somatostatin analogue, is highly effective in the therapy of growth hormone/prolactin-secreting pituitary adenomas. Clin. Cancer Res. 13,2738-2744. 

De Camilli P, Macconi D, Spada A (1979) Dopamine inhibits adenylate cyclase in human prolactin-secreting pituitary adenomas. Nature 278 252-254. 

Keye WR Jr, Chang RJ, Wilson CB, Jaffe RB. Prolactin-secreting pituitary adenomas III. Frequency and diagnosis in amenorrhea-galactorrhea. JAMA 1980 244 1329-32. 

Transsphenoidal pituitary surgery is the treatment of choice for TSH-secreting adenomas. Pituitary gland irradiation is often given following surgery to prevent tumor recurrence. Bromocriptine has been used to treat tumors that co-secrete prolactin. 

Cannavo S, Curto L, Squadrito S, et al. CabergoUne A first-choice treatment in patients with previously untreated prolactin-secreting pituitary adenoma. J Endocrinol Invest 1999 22 354-359. 

Prolactin has no therapeutic uses. Hyperprolactinemia is a relatively common endocrine abnormality that most often is caused by prolactin-secreting pituitary adenomas. Hyperprolactinemia also can result from hypothalamic or pituitary diseases that interfere with the delivery of inhibitory dopaminergic signals primary hypothyroidism associated with increased TRH levels renal failure treatment with dopamine receptor antagonists. Manifestations of prolactin excess in women include galactorrhea, amenorrhea, and infertihty. in men, hyperprolactinemia causes loss of libido, impotence, and infertility. 

A case of reduced prolactin levels has been reported in a man treated with fluphenazine and benzatropine who took bromocriptine to treat a pituitary tumour. His prolactin level became undetectable, and his psychiatric status was unchanged, although no reduction in tumour size was seen with the bromocriptine. However, the prolactin levels of a patient with a prolactin-secreting pituitary adenoma fell from almost... 

Prolactin-producing hypophyseal adenoma (prolactinoma) is the most common functional pituitary adenoma. Its prevalence peaks in women between 20 and 30 years of age. Hyperprolactinemia can be a cause of infertility and is associated with diminished gonadotropin secretion, secondary amenorrhea, and galactorrhea. The patient should first be examined for drug-induced hyperprolactinemia before any infertility work-up is initiated. For example, antidepressants, cimetidine, dopamine antagonists, reser-pine, sulpiride, verapamil, methyldopa, and estrogen therapy are known to interface with prolactin secretion. 

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