I had 15 cc's aspirated from a "chocolate" cyst in my thyroid. any reason to be concerned? it doubled in size in 3 wks. waiting on pathology

Thyroid cysts: Most cystic lesions in the thyroid are benign, and because the thyroid is so vascular, may often have degenerated blood in the contents. They may also recur following aspiration. The important thing is to exclude the chance that a low grade cancer is the source of the abnormal fluid. To do this, a needle aspiration biopsy of the cyst wall/boundary is done, sometimes with ultrasound guidance.