In November of 2006 I had a right thyroid lobectomy because of a nontoxic multinodular goiter that was growing and affecting my swallowing and voice. I also have nodules on my left lobe. I have regular sonograms, but at the last one, two weeks ago, the technician told me I had a significant amount of tissue on my right side - he thought I was mistaken about having a lobectomy. When I saw my surgeon last week, he was quite surprised to learn there was a growth of tissue from the previous sonogram of approximately 2 mm (which was left to protect the nerve) to over 4 cm. What is growing there? He doubled my medication from .5 mcg to 1.0 mcg, will redo the sono in three months and do another biopsy if there is continued growth. How worried should I be, and should I wait out the three months, or make an appointment with an Endocronologist?