• transsphenoidal surgery is the mainstay of treatment
  
  
• if the tumour is small (< 1 cm in diameter) then surgery is likely to result in postoperative growth hormone levels of < 5 mU/l
  • small non-invasive tumours carry a favourable surgical prognosis with 80 per cent of microadenoma (<1cm diameter) removals achieving serum GH levels below 5mU per litre
  • this compares with, acceptable serum GH levels being achieved in less than 50 per cent of subjects following pituitary macroadenoma removal
• factors influencing postsurgical GH concentration include:
  • pituitary tumour size
  • degree of extrasellar extension (particularly into the cavernous sinus)
  • high presurgery serum GH levels.
    
    
• 30% chance of loss of pituitary function when surgery for large intrasellar and extrasellar tumours
  
  
• mortality from pituitary surgery is low and postoperative complications such as hypopituitarism, diabetes insipidus and cerebrospinal fluid leaks or meningitis are uncommon
  
  
• surgical ‘cure’ rates for pituitary macroadenomas are at best 60 per cent
  • however debulking remains important as the probability of additional treatments achieving acceptable serum GH levels is dependent on circulating GH levels at the time this treatment is commenced
  • note that if optic chiasm compression is present, surgical debulking is of major importance in restoring or protecting vision

Reference:

1. Prescriber (2003): 14(13):55-62.