thyroglossal cyst Flashcards
how would a thyroglossal cyst present?
painless swelling (fluid-filled tissue) moves up when swallow + stick tongue out
what is a thyroglossal cyst?
fibrous suture
during embryonic development, thyroid gland migrates form foramen cecum to neck, and thyroglossal duct would normally disappear, but cyst appears if duct remains
where does thyroglossal cyst form?
anywhere along duct
most commonly just inferior to hyoid
what does the thyroglossal duct join?
descending thyroid to tongue
where does primordium of thyroid appear prior to descend?
foramen cecum of sulcus terminalis of tongue
between tuberculum impar (PhA1 median) and cupola (PhA2,3,4 median)
why would a thyroid gland nodule / lump move up on swallowing?
stylopharyngeus contracts when swallow (attaches to thyroid cartilage, moving thyroid)
inner circular pharyngeal muscle
why would cyst move up when tongue is protruded?
as thyroglossal cyst is still connected to back of tongue (not obliterated)
how can you tell if there is active thyroid tissue within cyst?
whether there is radioactive iodine in the swelling
yes = active
where do you find thyroglossal cysts?
midline of SCM
along thyroglossal duct
what is a thyroglossal fistula?
opens to surface
cyst = just fluid filled, enclosed
how do thyroglossal cysts differ from branchial cysts?
thyroglossal: midline
branchial: border of SCM, below angle of jaw
what are branchial cysts?
Ph cleft 2 proliferates to overlap Ph clefts 3 + 4
if cervical sinus not obliterated properly = branchial cyst
why would you be concerned about lymphadenopathy in the neck?
malignancy / infection
of structures anywhere in neck can lead to enlarged lymph nodes (superficial / deep)
what do deep cervical lymph nodes drain?
almost all lymph form H+N region
how do most thyroid cancers show in radio-active isotope scanning?
absence of radio-active iodine ‘cold spots’
carry out biopsy / aspiration of lump if uncertain
