A multinodular goiter is a multinodular enlargement of the thyroid gland.
The multinodular goiter can be associated with hyperthyroidism ("Toxic multinodular goitre") or not.
It is a non-tumoral condition but a thyroid cancer is identified in 13.7% of the patients operated for multinodular goiter. these nodules grow up at varying rates and secrete thyroid hormone autonomously thereby suppressing TSH dependent growth and function in the rest of gland.
References
Multinodular goitre Wikipedia(Text) CC BY-SA