Hyperprolactinemia, Prolactinoma

In the following, hyperprolactinemia and prolactinoma are presented together, because prolactinoma is always accompanied by hyperprolactinemia.

Hyperprolactinemia (synonyms: pathologic prolactin elevation; prolactin excess; ICD-10-GM E22.1: hyperprolactinemia) is a pathologic (abnormal) elevation of prolactin levels. Causes are often drugs (which cause functional disinhibition due to decreased dopamine levels in the pituitary gland; see Causes) and rather rarely prolactinomas.

The prevalence (disease frequency) of hyperprolactinemia is less than 1%; in women with hypothyroidism (underactive thyroid gland) about 65-70%, in women with amenorrhea (no menstrual bleeding for more than three months with an already established menstrual cycle) and galactorrhea (abnormal breast milk discharge) 75%. 30% of patients with galactorrhea have prolactinoma.

Physiologic causes of hyperprolactinemia are:

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

In prolactinoma (synonyms or theasaurus terms: Azido-basophilic adenoma; Azidophilic adenoma; Basophilic adenoma; Benign pituitary tumor; Chiasm compression by pituitary adenoma; Chromophobic adenoma; Chromophobic pituitary adenoma; Eosinophilic adenoma; Eosinophilic pituitary adenoma; Forbes-Albright syndrome; Galactorrhea-amenorrhea syndrome; Benign neoplasm of pituitary fossa; Benign neoplasm of pituitary gland; Benign neoplasm of Rathke’s pouch; Benign neoplasm of cerebral appendage; Pituitary adenoma; Intrasellar benign neoplasm; Macroprolactinoma syndrome; Mucoid cell adenoma;Prolactin-producing adenoma; ICD-10-GM D35. 2: Benign neoplasm of other and unspecified endocrine glands: pituitary gland) is a benign neoplasm of the anterior lobe of the pituitary gland (pituitary gland). These tumors originate from the lactotropic cells of the pituitary gland.

Prolactinoma is the most common endocrine active tumor of the pituitary gland (40% of all pituitary tumors; 10-15% of all brain tumors). Usually, these tumors are benign (benign). Based on size, prolactinomas are classified as follows:

  • Microprolactinoma < 1 cm (→ prolactin in serum: < 200 ng/ml).
  • Macroprolactinoma ≥ 1 cm (→ prolactin in serum: > 200 ng/ml).

Other causes of hyperprolactinemia include:

  • Functional disinhibition due to decreased dopamine levels in the pituitary gland from medications (see under etiology/causes).
  • Alterations of the hypothalamus or interruptions of the pituitary stalk.
  • Diseases (e.g., hypothyroidism/ hypothyroidism, chronic renal failure/renal insufficiency, etc.).

Sex ratio for prolactinoma: males to females is 1: 5.

Peak incidence for prolactinoma: The disease occurs predominantly in the 3rd and 4th decade of life.

The incidence (frequency of new cases) for prolactinoma is approximately 3 cases per 100,000 population per year (in Germany).

Course and prognosis: The prognosis depends on the cause. In women, galactorrhea (abnormal breast milk discharge) occurs in 30% of cases, as well as a cycle disorder (oligomenorrhea (the interval between bleeding is > 35 days and < 90 days) with anovulation (absence of ovulation), possibly also amenorrhea/no menstrual bleeding for more than three months with an already established cycle). In men, disturbances in sexual activity with loss of libido and potency are in the foreground, which can lead to conflicts in the partnership. In men, gynecomastia (enlargement of the mammary gland) may also occur. In the majority of cases, the course of the disease is good.