what to do about a pituitary tumor, that had been overlooked for years and treated as a hypothyroid, though when checking the free t4, it was twice the normal high. High tsh and High free t4. I finally after ten years of being treated with levothyroxine because my tsh was high at times, begain going into a-fib and ending up at er's to be converted. It is now determined that the excessive levothyroxine I'd been taking was triggering it. I've just begun to see and endocrinologist who had my pituitary gland scanned by an MRI and a small tumor was detected. He took me off the thyroid medicine and monitored it for six weeks and then put me on 10 mgs of Methimazole or Tapazole and then monitored it another six week and now has decided to try 10 mgs. twice a day and levothyroxine 125 mcgs once a day. The Dr. said that I was a very rare case and that in his 40 years of practice as an Endocrinologist, he's seen one like me just three times, once while in training, once in his practice and me being the third. Today is the day I've started the new meds, and I certainly hope it works. I've had so many different ailments over the years that maybe some of them can be controlled...Fingers crossed, here's hoping.