Hello I have gone through your question. Your thyroid condition is complex because you have low thyroid and multinodular goitre. In my opinion in your case,it is possible that you have coexistent Hashimoto thyroiditis and Multinodular goitre. Anyway,i have not seen your thyroid test results and this is what i suppose.I m sure that your treating doctor has reached the right dignosis and the test results had clarified all the diagnosic doubts. About your question,i can say that it is rare to find cancer in a multinodular goitre,most nodules and swellings are harmless,but if the thyroid gland is growing rapidly it is always best to have them checked promptly in case they are among the few that are cancerous. If a patient like you,come to my clinic i recommend to do an neck ultrasound to see the structure of the thyroid gland and to examine the nodules. This simple and painless test can give important information on the likelihood that a nodule is benign or a cancer. Other important test for the diagnosis (if it is cancer or not) is Fine needle aspiration cytology (FNAC) or better ultrasound guided FNAC. If one or more of nodules raises concern following investigation, then surgery may also be recommended. My advice for you is to consult your treating endocrinologist with a minimum of delay. Hope i have clarified all your doubts. If you have other questions,feel free and ask. Take care.