The ultrasound of thyroid masses.

Ultrasonography of the thyroid gland permits differentiation between cystic, solid, and mixed lesions, allowing conservative management of cystic lesions, which constitute 20% of hypofunctioning nodules. The combination of ultrasonography and fine needle aspiration cytology appears to be a great advance in the preoperative diagnosis of nontoxic goiter and permits individualized treatment in as precise a manner as is possible at present.