Hyperprolactinemia, Prolactinoma: Causes

Hyperprolactinemia

Pathogenesis (disease development)

Prolactin (PRL, synonyms: lactotropic hormone (LTH); lactotropin) is a hormone from the anterior pituitary (HVL) that acts on the mammary gland and controls milk production in women after pregnancy.Prolactin itself is inhibited by prolactin inhibiting factor (PIF), which is produced in the hypothalamus (section of the diencephalon near the optic nerve junction). This is identical to dopamine. Hyperprolactinemia thus develops as follows:

  • Autonomous pituitary prolactin secretion (see prolactinoma below).
  • Impaired hypothalamic dopamine release or impaired transport to anterior pituitary → omission of prolactin inhibiting factor (PIF).
  • Increased hypothalamic stimulation of prolactin cells that outweighs physiological inhibition of prolactin secretion. A good example is hypothyroidism (hypothyroidism) with hyperplasia (excessive cell formation) of the thyrotropic cells of the anterior pituitary (lack of negative feedback by T3 → TRH hypersecretion).

Physiological causes of hyperprolactinemia are:

  • Tactile stimulation of the female nipple (massaging the female nipple).
  • Pregnancy
  • Stress (physical and/or psychological)

Etiology (causes)

Biographical causes

  • Genetic burden – mutations in the prolactin receptor gene (PRLR).

Behavioral causes

  • Nutrition
    • Heavy, high-protein meals
  • Stimulants
    • Stronger alcohol consumption
  • Psycho-social situation
    • Stress

Disease-related causes

Endocrine, nutritional and metabolic diseases (E00-E90).

  • Acromegaly – endocrinologic disorder caused by overproduction of growth hormone (somatotropic hormone (STH), somatotropin), with marked enlargement of the phalanges or acras, such as the hands, feet, lower jaw, chin, nose, and eyebrow ridges.
  • Primary hypothyroidism (primary hypothyroidism) – primary hypothyroidism is generally referred to when the thyroid gland itself is causative for hypothyroidism → lack of negative feedback by T3 → TRH hypersecretion.
  • Subclinical (latent) hypothyroidism (hypothyroidism) → lack of negative feedback by T3 → TRH hypersecretion.
  • Empty sella syndrome – this involves expansion of the subarachnoid space into the sella turcica; this may result in endocrine dysfunction

Factors affecting health status and leading to health care utilization (Z00-Z99).

  • Stress

Liver, gallbladder and bile ducts – Pancreas (pancreas) (K70-K77; K80-K87).

Neoplasms – tumor diseases (C00-D48).

  • Tumors of the parasellar/suprasellar region – area of the base of the skull called the “Turk’s saddle”.

Psyche – nervous system (F00-F99; G00-G99).

  • Epileptic seizures, unspecified.
  • Lymphocytic pituitaryitis – inflammation of the pituitary gland.

Pregnancy, childbirth and puerperium (O00-O99).

  • Pregnancy
  • Breastfeeding

Genitourinary system (kidneys, urinary tract – sex organs) (N00-N99)

Injuries, poisonings, and other consequences of external causes (S00-T98).

  • Injuries to the brain, unspecified
  • Pituitary stalk and hypothalamic lesions (tumor, trauma, radiotherapy/radiotherapy).

Other causes

Medication

Prolactinoma

One can distinguish a microadenoma (microprolactinoma: < 1 cm) from a macroadenoma (macroprolactinoma: > 1 cm). The tumors originate from the lactotropic cells of the pituitary gland.Only about five percent of microprolactinomas develop into macroprolactinomas. The adenoma secretes only prolactin in most cases (prolactinoma) and GH (growth hormone) and prolactin in rare cases (acromegaly).