Thyroglossal Cysts

Question 1

Define Thyroglossal cysts

Answer 1

Congenital disorder of the thyroglossal duct, whereby there is failure of closure of the thyroglossal duct, forming a cyst filled with mucus

Question 2

Aetiology of Thyroglossal cysts

Answer 2

Failure of closure of the thyroglossal duct, which would be open for descent of the thyroid gland.
The epithelial cells that line the duct produce mucus -> cyst

Question 3

Symptoms of a Thyroglossal cyst

Answer 3

Often after local inflammation of URTIs (always present, only present on exacerbations)

Painless lump/swelling, Painful if infected
Dysphagia (rare)
Fever (infection)

Thyroid tumour (if thyroid gland fails to descend)

Question 4

Signs of a thyroglossal cyst on examination

Answer 4

Painless lump/swelling

• Often subhyoid or suprahyoid
• Found mainly in the midline
• Solitary and cystic
• Moves on swallowing AND protrusion of the tongue
• Erythema and tender if infected

Question 5

Investigations for a thyroglossal cyst

Answer 5

USS: cyst seen (well-circumscribed, echoic midline mass above the hyoid)
CT: thyroglossal cyst

Fine needle aspiration: diagnostic

TFTs: normal - check for thyroid tumour