Being that your nodule has grown....it can definitely get larger than that. My largest nodule is over 3cm. The issue with large nodules is that they can eventually affect breathing if they block the airways. Also, a biopsy of the nodule is necessary to detect any abnormal cells that may develop. Please talk to your Endocrinologist regarding the disadvantages of a thyroid nodule.
I have seen them larger on here..Mine is 8mm it was 1.1cm but has shrunk for now with meds, will be looked at again in a few months to check again..Are you having a biopsy on this..Dawn