For a TSH producing microadenoma, would you recommend surgery vs methimazole if the patient is elderly and the tumor is relatively small?  

The female patient is in her late 70s with cardiac disease (likely due to chronic hyperthyroidism that was missed due to non-suppressed TSH). I’ve diagnosed and found the TSH adenoma and started methimazole and she is clinically much improved. Do I just follow her clinically on methimazole or send for surgical resection of the pituitary tumor?