Pituitary Disorders

Pituitary Disorders

Acromegaly

• – Pathway/Axis:
  • Growth hormone
• – Major cause:
  • tumor of the anterior pituitary gland called a pituitary adenoma.
  • Causes anterior pituitary to produce excess growth hormone after the closure of the epiphyseal plate during puberty.
• – Major symptoms:
  • hands, feet, nose, lips, and ears show swelling of the soft tissue, and skin starts to thicken.
  • Swelling if internal organs, deep voice due to swelling of vocal cords, jaw or brow protrusion, and expansion of the skull at the fontanelle.
  • Enlargement of the tongue. Severe headaches, arthritis, hypertension, diabetes mellitus. Possible heart and kidney failure.

Empty Sella Syndrome

• Path:
  • Primary – Defect w/ extension of dura into sella -> pressure atrophy of pituitary tissue -> hypopituitarism
  • Secondary – Radiation, injury, or surgery -> regression of pituitary gland -> hypopituitarism

Hypopituitarism

• Causes:
  • 1) Injury (TBI, tumor, radiation, stroke) -> decrease of releasing hormones from the hypothalamus 
    
  • 2)Brain tumors affecting the hypothalamus 
    
  • 3) Stroke 

Lymphocytic hypophysitis

• Path:
  • an autoimmune disorder causing pituitary inflammation and necrosis 
  • – Abundant cells w/ blue nuclei due to lymphocytic infiltration 
    
  • – Necrosis and fibrosis
• Management:
  • Corticosteroids

Pituitary dwarfism

• – Pathway/Axis:
  • Hypothalamic/Pituitary/Liver (HPL) Axis
    
• – Major cause:
  • deficiency in growth hormone secretion from the anterior pituitary gland
    
• – Major symptoms:
  • below-average growth, normal body proportions, immature appearance, chubby body build prominent forehead, underdeveloped sexual organs.

Sheehan syndrome

• Path:
  • – Ischemic necrosis of pituitary in the postpartum period 
    
  • – Can occur w/ acute blood loss during delivery & inadequate perfusion
• Presentation:
  • – Decreased prolactin production -> decreased milk production
    
  • – Decreased FSH and LH production -> menses do not resume postpartum
• Management:
  • Hormone replacement for life

Pituitary Cancers

Pituitary adenoma (Prolactinoma)

• Results in:
  
  • – Pressure necrosis 
    
  • – Headache 
    
  • – Optic chiasm compression -> bitemporal hemianopsia 
    
  • – Pituitary apoplexy: acute spontaneous hemorrhage of pituitary due to enlarging adenoma 
• Management:
  • Prolactinoma:
    • Dopamine agonist:
      
    • Cabergoline (faster)
      
    • Bromocriptine (safer)
  • Non-functioning tumor:
    • Observe with MRI and prolactin levels

Pituitary apoplexy

• Path:
  • acute spontaneous hemorrhage of pituitary due to enlarging adenoma
• Results in:
  
  • – Sudden onset of severe headache 
    
  • – Visual field loss and diplopia 
    
  • – Acute hypopituitarism 
    
  • – Cardiovascular collapse due to decreased ACTH
• Management:
  • Stress dose glucocorticoid
    
  • Endocrine and Neurosurg consult

Pituitary during pregnancy

• – Increased estrogen -> hyperplasia of prolactin-secreting cells -> increased prolactin -> INCREASED PITUITARY SIZE
• – Vascular supply remains the same despite the increased pituitary size