Thyroid and lymph nodes left side neck removed due to thyca last year. us shows 17 swollen lymph nodes 3-14mm looking benign both sides neck. cancer?

Hard to say: Certainly nodes that are enlarging would be a cause for concern and likely further workup. US is not very good at characterizing benign vs malignant thyroid or lymph tissue; consult with your endocrinologist or surgeon, as a biopsy of one or more nodes could be in order.

FNA: Hi. Of course you could have a viral or bacterial upper respiratory tract infection (which would usually have accompanying symptoms), so waiting several weeks to recheck is fine. However, with your history, I'd be tempted to do FNAs of the large lymph nodes for cytology and include needle washing for thyroglobulin. Talk with your endocrinologist who's running the show. She/he will plan accordingly