What does diffuse thyromegaly mean in thyroid scintigraphy?

Image enlarg thyroid: Thyromegaly means enlargement of thyroid gland sometimes called goiter. Most commonly enlarged gland caused by hyperthyroidism sometimes called Graves' disease.Most common cause of goiter worldwide is lack of iodine in the diet.In US, where the use of iodized salt is common,goiter more often due to the over- or underproduction of thyroid hormones or to nodules (diffuse multinodular goiter.