One type of nodule
Colloid is a yellow-brown liquid found in thyroids.
Thyroid cells usually organize into hollow balls, or follicles, with colloid in their centers. Occasionally, cysts (large liquid-filled structures) can form in the thyroid. These often are filled with colloid, and may be called colloid cysts. Most cysts are not cancers, but 5% can have a cancer
along an edge. A biopsy
(fna) can determine this.