We present the case of a 61yo womanwith an incidental non-functioning pituitary macroadenoma that spontaneously resolved on serial imaging over a 3-month period. There is little documenting the natural history of non-operated pituitary macroadenomas, however it can be inferred from post operative regrowth studies that adenomas tend to be static or grow gradually over time1. We were unable to find any reports of spontaneous resolution of macroadenoma in the absence of apoplexy in a brief literature review.
The patient presented with altered conscious state due to meningoencephalitis. CT Brain revealed an incidental sellar mass, confirmed on MRI to be a pituitary macroadenoma measuring 11 x 19 x 18mm (AP x trans x SI), with compression of the optic chiasm and no evidence of haemorrhage.
Ophthalmologic visual field assessment confirmed a bitemporal superior quadrantanopia.
Initial cortisol was 196nmol/L (85-460) with ACTH 9pmol/l (<20) in the setting of acute illness so stress dose steroids were commenced. Pituitary hormones were difficult to interpret in the setting of acute illness, however there was evidence of possible secondary hypothyroidism (T4 8.1pmol/L (10-19), T3 2.5 pmol/L (3.5 – 6.5), TSH 1.54mIU/L (0.5 – 4)), gonadotrophins were inappropriately low for a post menopausal woman (FSH 15IU/L (> 20), LH 5IU/L (>20)), with normal prolactin (117mIU/L (59-619)), IGF1 (12nmol/L (5-32)), and GH (4mIU/L (0-21)).
Steroids were ceased on day 10 given a mane cortisol of 456nmol/L after withholding the afternoon dose of hydrocortisone the day prior.
Subsequent MRI Brain 2 weeks into admission showed the lesion had halved in size (14 x 9 x 9.5mm), this was stable on imaging 4 weeks and the lesion had completely resolved by 3-month follow-up with resolution of visual changes and normalised pituitary hormone profile.
This represents a unique case of documented spontaneous involution of pituitary macroadenoma in the absence of apoplexy.