I have a tyroid nodule, 1.6 x .9 x 3 cm. heterogeneously attenuating predominantly cystic right thyroid nodule. what's it mean and could it be cancer?

Biopsy: Most likely is benign lesion but for definitive diagnosis you should have biopsy.

Thyroid: Its highly unlikely to be cancer. The odds favor this being a thyroglossal duct cyst. Pts often present at you age. You don't say where exactly your mass is. TDC is usually near midline. Another possibility is a branchial cleft cyst which is also a congenital problem. Your docs may want to do a CT guided fine needle biopsy. Hang in there. I think you will be fine.