Endocrine: Pituitary Pathology

Pituitary Adenoma

Classification

  • Function:
    • Nonfunctional (Generally Present as Clinically Nonfunctioning with Rare Symptoms from Hormone Hypersecretion)
      • Gonadotroph Adenoma
      • Thyrotroph Adenoma
    • Functional – Most Common
      • Lactotroph Adenoma
      • Somatotroph Adenoma
      • Corticotroph Adenoma
  • Size:
    • Microadenoma (< 1 cm)
    • Macroadenoma (≥ 1 cm)
    • Giant (> 4 cm)

Symptoms of Mass Effect

  • Headache
  • Bitemporal Hemianopia – From CN II Compression
  • Mildly Decreased Hormone Release

Diagnosis

  • Dx: MRI & Hormonal Labs
  • Hormonal Evaluation:
    • Lactotroph Adenoma: Serum Prolactin > 200 ng/mL
    • Somatotroph Adenoma: Serum Insulin-Like Growth Factor 1 (IGF-1)
    • Corticotroph Adenoma: *See Endocrine: Hypercortisolism
  • Associated with MEN-1 Syndrome

Nonfunctional Tumor

  • Nonfunctional Tumors are Most Commonly Identified as Macroadenomas
  • Primarily Present with Symptoms of Mass Effect
  • Treatment:
    • Symptomatic: Transsphenoidal Resection
      • Primary Indications: Impaired Vision or High Risk for Vision Loss
      • May Require Adjuvant Radiation
    • Asymptomatic: Consider Annual MRI to Monitor vs Surgery

Lactotroph Adenoma (Prolactinoma)

  • Hypersecretion of Prolactin
  • Most Common Functional Adenoma & Most Common Adenoma Overall
  • Presentation:
    • Females:
      • Infertility
      • Amenorrhea
      • Galactorrhea
    • Males:
      • Low Libido/Impotence
      • Infertility
      • Gynecomastia
      • Galactorrhea
  • Treatment:
    • Asymptomatic & < 1 cm: Follow with MRI
    • Symptomatic or > 1 cm: Medical Treatment – Dopamine Agonist (Bromocriptine or Cabergoline)
      • If Fails: Transsphenoidal Resection

Somatotroph Adenoma

  • Hypersecretion of Growth Hormone
  • Presentation:
    • Acromegaly (In Adults)
      • Thickened Skin
      • Coarse Facial Features & Enlarged Jaw (Macrognathia)
      • Enlarged Hands (Need to Enlarge Rings)
      • Enlarged Feet (Increased Shoe Size)
      • Broad Bones
      • Hypertension
      • Cardiomyopathy
      • Diabetes
      • Obstructive Sleep Apnea
    • Gigantism (In Peds)
      • Dramatic Vertical Growth
      • Obesity
      • Macrocephaly
  • Treatment: Transsphenoidal Resection

Corticotroph Adenoma

Pituitary Adenoma 1

Acromegaly Facial Features 2

Gigantism 3

Other Pituitary Pathology

Pituitary Apoplexy (“Sudden Attack”)

  • Sudden Hemorrhage or Infarction of the Pituitary Gland
  • Risk Factors:
    • Pituitary Adenoma (Most Common)
      • May Occur After Radiation Therapy
    • Hypertension
    • Major Surgery
    • Medications
    • Head Trauma
  • Presentation:
    • Sudden Excruciating Headache
    • Diplopia & Decreased Visual Acuity
    • Altered Mental Status
    • Nausea & Vomiting
    • Hormone Deficiencies (Minority are Clinically Significant)
    • Hemodynamic Shock – From ACTH Loss
  • Diagnosis: MRI/CT
  • Treatment: Steroids & IVF
    • May Require Surgical Decompression for Severe Vision Changes or Neurologic Symptoms

Sheehan Syndrome

  • Pituitary Gland Infarction Due to Postpartum Hemorrhage (Typically Large Losses)
    • Pituitary Hypertrophies While Pregnant
  • Presentation:
    • Lactation Failure (Most Common Symptom)
    • Failure to Resume Menses/Amenorrhea
    • Lethargy & Fatigue
    • Weight Loss
    • Hypothyroid
  • Treatment: Hormone Replacement

Nelson Syndrome

  • Pituitary Gland Hypertrophy After Bilateral Adrenalectomy for Cushing Disease
    • Loss of HPA Axis Feedback Causes Increased CRH/ACTH Production
    • Generally Occurs 1-5 Years Postoperatively
  • Presentation:
    • Hyperpigmentation (Most Overt Symptom)
      • From ACTH Conversion to CRH
      • May Cause a Prominent Linea Nigra from the Pubis to Umbilicus
    • Headache
    • Diplopia & Decreased Visual Acuity
    • Amenorrhea
  • Diagnosis: Increased ACTH After Surgery & MRI
  • Primary Treatment: Transsphenoidal Resection
    • If Surgery Not an Option: Radiation or Medical Therapy

Craniopharyngioma

  • Solid/Cystic Tumor from the Remnant of Rathke’s Pouch
    • Rathke’s Pouch: Ectoderm That Becomes Anterior Pituitary
  • Presentation (From Mass Effect):
    • Headache
    • Bitemporal Hemianopia – From CN II Compression
    • Mildly Decreased Hormone Release
  • Diagnosis: MRI/CT
  • Primary Treatment: Transsphenoidal Resection
    • May Require Adjuvant Radiation for Residual Disease

Pituitary Apoplexy 4

Craniopharyngioma 5

References

  1. Chanson P, Salenave S. Wikimedia Commons. (License: CC BY-2.0)
  2. Chanson, P., Salenave, S. Acromegaly.Orphanet J Rare Dis 3, 17 (2008). Wikimedia Commons. (License: CC BY-2.0)
  3. de Herder WW. Acromegalic gigantism, physicians and body snatching. Past or present? Pituitary. 2012 Sep;15(3):312-8. (License: CC Not Specified)
  4. Berg KT, Harrison AR, Lee MS. Perioperative visual loss in ocular and nonocular surgery. Clin Ophthalmol. 2010 Jun 24;4:531-46. (License: CC Not Specified)
  5. Garnett MR, Puget S, Grill J, Sainte-Rose C. Craniopharyngioma. Orphanet J Rare Dis. 2007 Apr 10;2:18. (License: CC BY-SA-2.0)