Flashcards in 1. Thyroid development Deck (17):
Thyroid diverticulum arises from ... ( and course)
floor of primitive pharynx ( descends into neck )
thyroid diverticulum direction ( after arising)
descends into neck
what is Thyroid diverticulum ?
embryological structure from which thyroid follicular cells derive
thyroiglossal duct - function
connects developing thyroid ( as it travels) to tongue
thyroglossal duct - fate
normally disappears ( normal remnant is the foramen cecum ) but may persist as pyramidal lobe of thyroid or as a cyst
normal remnan of thyroid duct
MC ectopic thyroid tissue site is the
tonhue ( lingual thyroid)
thyroglossal duct cyst present as an
anterior midline neck masss that moves with swallowing or protrusion of the tongue
thyroglossal duct cyst results from
failure of normal developmental obliration of the thyroglossal duct
persistent cervical sinus lead to
branchial cleft cyst
thyroglossal duct cyst vs branchial cyst (according presentation )
thyroglosal duct cyst : anterior midline, moves with swallowing or protrusion of the tongue
branchial cleft cyst : lateral neck, not move
Describe the embryologic origin of the thyroid gland.
The thyroid diverticulum arises from the floor of the primitive pharynx and then descends into the neck
A 20-year-old woman presents with an anterior midline neck mass. On examination, you notice that the mass moves with swallowing. Diagnosis?
Thyroglossal duct cyst
A patient undergoes a radioactive iodine thyroid uptake scan, which shows ectopic thyroid tissue. Where is it most likely located?
The tongue, which is the most common site of ectopic thyroid tissue
How can a thyroglossal duct cyst be differentiated from a branchial cleft cyst on physical examination?
A thyroglossal duct cyst is anterior and moves with swallowing; a branchial cleft cyst is in lateral neck and does not move with swallowing
• You are observing a thyroid surgery. The surgeon points at a "thyroid pyramid" and asks of what is it a remnant. What is your reply?
The pyramidal lobe of the thyroid can be a persisting remnant of the thyroglossal duct