Goiters can be present at birth or develop later in life. Iodine is necessary for the the thyroid to make it's hormones and with iodine insuff iciencency, a goiter will develop as the brain tries to stimulate the thyroid to make it's crucial hormones. In general, having a goiter increases the risk of thyroid cancer. While any growing nodule in the thyroid is suspicious for cancer, most are benign. Radiation Exposure is a risk factor for developing thyroid cancer.
Radiation causes changes in the genes of the thyroid cells, and increases the chance for nodules.
Some young Japanese who survived the atomic bomb later developed it. Radiation is linked to slow growing thyroid cancer that often takes 10 - 30 years after the exposure to become apparent. Twenty percent of thyroid cancer patients have a family history of goiter. Anything that irritates the thyroid gland over time will increase cancer risk. Early thyroid cancer usually has no symptoms, it is just a small lump in the thyroid.