Tests of prolactin secretion in diagnosis of prolactinomas.
Prolactin-secreting tumours of the pituitary were identified and treated by transsphenoidal microsurgery in fourteen infertile females with hyperprolactinaemia. Resting prolactin levels were 590--9000 mU/1 (mean 3400). In seven patients, tomography of the pituitary fossa was normal and resting prolactin levels were 590-6000 mU/1 (mean 3400). In these patients the pre-operative diagnosis prolactinoma in these patients was made by demonstrating loss of the normal circadian prolactin profile and impaired prolactin response to intravenous thyrotrophin-releasing hormone (T.R.H.) and metoclopramide stimulation. Prolactin response to the acute oral administration of L-dopa and bromocriptine was of less diagnostic value. Preoperative assessment of anterior pituitary function identified abnormalities other than hyperprolactinaemia in four patients (28%). Post-operative assessment indicated that microsurgery was curative in twelve patients (86%), selective in all, and without significant side-effect. It is concluded that dynamic tests such as T.R.H. and metoclopramide stimulation have considerable value in identifying hyperprolactinaemic patients with prolactin-secreting adenomas, particularly those which are radiologically occult.
D000293:Adolescent; D000328:Adult; D001971:Bromocriptine; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007980:Levodopa; D008787:Metoclopramide; D009384:Paraneoplastic Endocrine Syndromes / Q000175:diagnosis*; D010901:Pituitary Function Tests / Q000379:methods; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*; D013268:Stimulation, Chemical; D013973:Thyrotropin-Releasing Hormone
D001971:Bromocriptine; D007980:Levodopa; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D008787:Metoclopramide