Pituitary adenoma

Physiology

•   See: Pituitary gland and the hypothalamus 

 

Pathophysiology

• The neoplasm occupies space in the skull and may raise intracranial pressure. 
• The neoplasm may compress the optic chiasm, blocking signal propagation from the lateral retinal cells.

 

• Neoplasia of pituitary cells may cause hyperpituitarism (excessive pituitary activity). 
• Adenoma may produce excessive human growth hormone (hGH):  Pituitary gigantism (before closure of the growth plates). Acromegaly (after closure of the growth plates). 
• Adenoma may produce excessive prolactin: Unexpected lactation (in women or men).
• Adenoma may produce excessive cortisol: Hypercortisolism (Cushing's disease).

• Compression of normal pituitary cells may cause hypopituitarism (insufficient pituitary activity).
• Adenoma may disrupt human growth hormone (hGH) production: Pituitary dwarfism.
• Adenoma may disrupt prolactin production: Failure to lactate.
• Adenoma may disrupt production of follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH): Infertility.
• Adenoma may disrupt cortisol production: Hypocortisolism (Addison's disease).  

 

Symptoms and signs

• Headache (various types, various mechanisms)
• Visual field defects, classically bitemporal hemianopia (optic chiasm compression)

• Hyperpituitarism
• Gigantism
• Acromegaly
• Unexpected lactation (in women or men) 

• Hypopituitarism
• (Proportional) dwarfism
• Oligo- or amenorrhoea 
• Infertility 
• Failure to lactate