Relevant Physiology

Physiology

Etiology

• Anterior Pituitary Diseases

  • Prolactinoma ↑

    • Effect on Prolactin is size-dependent
      • < 1 cm: < 200 IU
      • 1-2 cm: 200-1000 IU

      • 2cm: > 1000 IU

  • Pituitary Stalk Effect

• Inhibition of dopaminergic neurons
  • Pregnancy and Lactation (Breast Feeding), stress (physiological)
  • Serotonin, Opioid (Narcotics), Histamine → often < 100 IU
• Direct stimulus on lactotrophs
  • Hypothyroidism ↓ → High level of TSH (< 5) stimulate prolactin production
  • Taking D2 antagonist → Prolactin often < 100 IU
  • Estrogen
• Decreased prolactin clearance:
  • !Liver Failure
  • CKD

Presentation

Signs and Symptoms

Anatomical

• Headache
• Pituitary Tumor Mass Effect

Physiological

• Anhedonia → Low motivation, low adherence (mesolimbic pathway)
• Sexual dysfunction (ED)
• Hypogonadism (due to inhibitory of prolactin effect on GnRH)
  • Oligo-amenorrhea
  • Infertility
• Galactorrhea
  • *Rule out breast cancer

Investigation

Tests

• Prolactin