Pituitary

Hypopituitarism

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Hypopituitarism, Panhypopituitarism, Pituitary Insufficiency, Sheehan Syndrome

  • Definitions
  1. Hypopituitarism
    1. Decreased or loss of pituitary Hormone secretion due to surgery, radiation, CNS mass, infarction or pituitary apoplexy
    2. Decreased Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), Somatotropin (GH) and Corticotropin (ACTH)
  2. Sheehan Syndrome
    1. Associated with severe Postpartum Hemorrhage with prolonged Hypovolemia, and secondary pituitary ischemia and necrosis
    2. Presents with peripartum failed Lactation, Fatigue and Hypotension; later Amenorrhea
    3. Severe cases may be associated with Adrenal Insufficiency
    4. Best outcomes with early pituitary Hormone Replacement
  • Causes
  1. Congenital
    1. Perinatal Injury
    2. Developmental Disorders
    3. Anencephaly
    4. Lipid storage disease
    5. Genetic
      1. PIT-1 (affects GH, TSH and Prolactin)
      2. PROP-1 (affects GH, LH, FSH, TSH, ACTH, Prolactin)
      3. HESX1 (affects GH, LH, FSH, TSH, ACTH, ADH)
      4. LHX3, 4 (affects GH, LH, FSH, TSH, Prolactin)
      5. PITX2 (affects GH, Prolactin)
      6. Isolated defects affect a single pituitary Hormone (>10 genetic defects identified)
  2. Trauma
    1. Closed Head Injury
    2. CNS Surgery
    3. Irradiation to brain, pituitary or nasopharynx
  3. CNS Mass (may be associated with pituitary apoplexy, CVA related dysfunction)
    1. Intrasellar
      1. Pituitary Adenoma
      2. Craniopharyngioma
    2. Parasellar
      1. Meningioma
      2. Optic Nerve glioma
    3. Metastatic cancer
      1. Breast Cancer
      2. Lung Cancer
      3. Melanoma
      4. Renal cell cancer
    4. Other malignancy
      1. Leukemia
      2. Lymphoma
      3. Germ cell tumors
  4. Ischemic Pituitary necrosis
    1. Postpartum Hemorrhage (Sheehan Syndrome)
    2. Diabetes Mellitus
    3. Sickle Cell Disease
    4. Temporal Arteritis
    5. Eclampsia
  5. Vascular conditions
    1. Cavernous Sinus Thrombosis
    2. Internal carotid aneurysm (intracranial)
  6. Infectious Disease
    1. Tuberculous Meningitis
    2. Malaria
    3. HIV Infection
    4. Fungal infections
  7. Infiltrative Disease
    1. Hemochromatosis
    2. Amyloidosis
    3. Lipid storage disease
    4. Granulomatous Disease
      1. Sarcoidosis
      2. Hypophysitis
  8. Miscellaneous Primary Causes
    1. Primary Empty Sella Syndrome
    2. Monohormonal idiopathic defects
  9. Miscellaneous Secondary Causes
    1. Nutritional Deficiency (Starvation, Anorexia Nervosa)
  1. See Hypothyroidism
  2. Fatigue
  3. Cold Intolerance
  4. Constipation
  5. Weight gain
  6. Alopecia
  7. Dry Skin
  8. Bradycardia
  9. Hoarse voice
  10. Cognitive slowing
  • Findings
  • LH or FSH Deficiency (Gonadotropin Deficiency)
  1. See Hypogonadotropic Hypogonadism
  2. Male
    1. See Male Hypogonadism or Testicular Failure
    2. Decreased sexual function and decreased libido
    3. Decreased Muscle mass
    4. Decreased Bone Mineral Density
    5. Decreased body hair
  3. Female
    1. See Premature Ovarian Failure
    2. Amenorrhea or Oligomenorrhea
    3. Infertility
    4. Decreased libido
    5. Osteoporosis
  1. See Growth Hormone Deficiency
  2. Child (Congenital GH Deficiency)
    1. Decreased linear growth
      1. Normal size at birth
      2. Subsequently falls off height growth curve
      3. Weight for age is preserved
    2. Episodic Hypoglycemia
    3. Prolonged Neonatal Jaundice
    4. Microphallus
    5. Midline craniofacial abnormalities
  3. Adult
    1. Fatigue
    2. Decreased Muscle mass and strength
    3. Increased visceral fat
    4. Premature atherosclerosis
  1. See Prolactin
  2. Lack of Breast alveolar milk secretion in pregnancy and failed Lactation
  • Labs
  1. Functional or stimulation tests are typically not needed for diagnosis
  2. Obtain Basal Hormone levels (morning Fasting levels)
    1. Growth Hormone (GH)
    2. Luteinizing Hormone (LH)
    3. Follicle Stimulating Hormone (FSH)
    4. Thyroid Stimulating Hormone (TSH) with reflex to Free Thyroxine (Free T4)
    5. Adrenocorticotropic Hormone (ACTH)
  • References
  1. Gounden (2021) Hypopituitarism, in StatPearls, Treasure Island, accessed 3/28/2022
    1. https://www.ncbi.nlm.nih.gov/books/NBK470414/
  2. Kim (2015) Endocrinol Metab 30:443-55 [PubMed]