Management of Acromegaly


Question

I am an Endocrinologist in private practice in Tucson. I was asked to see a patient for hyperthyroidism on Tapazole, he is a 64 year old male. He also has diabetes. When I evaluated him he appeared to be acromegalic, all of his testing confirmed acromegaly, including failure to suppress with glucose. Initial pituitary MRI demonstrated a small left sided pit. micro adenoma, 3x2 mm however when he was ready to undergo surgery he arrested with intubation. He has had 3 subsequent MRI's ,that fail to demonstrate a micro adenoma I suspect that the adenoma involuted. I have evaluated him for ectopic GH secretion with ct scans, octreoscan scan which have been normal. My question is whether I should continue to pursue an ectopic source of GH secretion or treat . I was planning on treating him with Sandostatin Lar. IGF-1 504, IgF Binding protein-3 6.6 TFT wnl. Of interest his IGF-1 level has remained elevated. The neurosurgeon is strongly suggesting pursuing ectopic eval. I was planning on treating him and following the IGF-1 levels. Your help with this case is appreciated, as far as any further testing that I may peruse Thank you very much, M Garcia MD

Response

thank you for your recent interesting question sent to EndoText. I presume that the GH and IGF-I levels have remained elevated after the initial attempted surgery with failure of suppression of GH after a glucose load, and with detectable GH levels in multiple testingover 12 hour period. If this is the case, it seems unlikely that there has been a spontaneous invlution of the microadenoma asthe biochemistry would indicate on-going active disease.

I would recommend measureing GHRH levels to determine if there is an ectopic source of the hypothalamic hormone. The important issue would be to initiate treatment and to assess the GH and IGF-I response to a somatostatin analogue such as you suggest. I trust you find these suggestions helpful in this interesting case. With kind regards. Paul J Jenkins