Health

What is the imaging technique of choice when a prolactin secreting tumor is suspected? Why? Magnetic resonance imaging (MRI) of the pituitary with a contrast agent, such as gadolinium, is the imaging technique of choice for the evaluation of pituitary tumors. In particular, discrimination of small tumors is improved. Computed tomography allows better visualization of …

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Why do men with prolactin secreting tumors often present with more advanced disease compared with women? The major symptoms of elevated prolactin values in men are decreased libido and impotence. These symptoms may be ignored or attributed to psychological causes. Many years may go by before an evaluation is sought, often when the patient experiences …

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What is galactorrhea? Do most patients with prolactin-secreting tumors present with this symptom? Galactorrhea is the discharge of milk from the breast not associated with pregnancy or lactation. Although a typical symptom of prolactin-secreting tumors, it may be absent in up to 50% of women, particularly when estrogen levels are very low. Galactorrhea is uncommon …

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How high prolactin result in gonadal dysfunction? What are the symptoms associated with gonadal dysfunction? Elevated prolactin levels suppress the hypothalamic–pituitary–gonadal axis primarily by interfering with the secretion of gonadotropin-releasing hormone in the hypothalamus, resulting in decreased circulating levels of gonadotropins and estrogen or testosterone. Symptoms include infertility, loss of libido, menstrual irregularity and amenorrhea …

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Causes of high prolactin levels What are the physiologic causes of an elevated prolactin level that must be considered in the differential diagnosis of prolactin-secreting tumors? What levels can be reached under these circumstances? The most important physiologic states in which prolactin is found to be elevated are pregnancy and lactation. During the third trimester …

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What are the normal levels of serum prolactin? Are they different in men and women? What levels are seen in patients with prolactin-secreting tumors? The normal serum prolactin level is < 15 or 30 ng/mL, depending on the laboratory. Women tend to have slightly higher levels than men, probably because of estrogen stimulation of prolactin …

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Normal control of prolactin secretion and how it is altered in prolactin secreting tumors? Multiple factors affect prolactin secretion. However, the principal influence on prolactin secretion is tonic inhibition by dopamine input from the hypothalamus. Dopamine interaction with receptors of the D2 subtype on pituitary lactotroph membranes activates the inhibitory G-protein, leading to decreased adenylate …

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