Embryology USMLE Step 1 Practice Question
A 3-week-old infant presents to the pediatric clinic with a mother concerned about a painless, firm midline neck mass. On examination, the mass is located between the hyoid bone and thyroid gland and moves upward when the infant cries and protrudes their tongue. Ultrasound confirms a cystic lesion with heterogeneous echotexture. The mother denies any recent infections or trauma. Based on the clinical presentation and anatomic location, the embryologic origin of this mass corresponds to remnants of a structure that normally regresses during fetal development. From which anatomic location does the thyroglossal duct normally originate?
Answer choices
- AThe epiglottis at the laryngeal inlet
- BThe foramen cecum at the junction of the anterior two-thirds and posterior one-third of the tongueCorrect answer
- CThe hyoid bone body at the level of the second branchial arch
- DThe lingual artery origin from the external carotid artery
- EThe thyrohyoid membrane attachment to the thyroid cartilage
- FThe cricothyroid junction at the inferior pharyngeal constrictor
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