Thyroid cysts

Question 1

What are the types of thyroid cysts?

Answer 1

(Simple cysts) exclusively fluid-filled nodules lined by benign epithelial cells.
(Complex cysts) partly solid and partly cystic and carry a 5–10% risk of malignancy

Question 2

What are the causes of thyroid cysts?

Answer 2

∼ 50% are due to cystic degeneration of thyroid tissue (colloid cyst)
∼ 40% are due to involution of a follicular adenoma
∼ 10% are due to thyroid cancer

Question 3

What are the clinical features of thyroid cysts?

Answer 3

Hemorrhage into a cyst → pain and rapid enlargement of the nodule
(large cyst or extensive hemorrhage)compression symptoms (e.g., hoarseness, dysphagia)

Question 4

How are thyroid cysts diagnosed?

Answer 4

(Ultrasound to assess size and appearance)
If low suspicion of malignancy but size > 2 cm → FNA
If high suspicion of malignancy and size > 1 cm → FNA :

Question 5

What is the treatment for thyroid cyst?

Answer 5

Aspiration

Surgery if aspiration not effective