A 7-Year-Old Child Is Brought to the Clinic for a Neck

A 7-year-old child is brought to the clinic for a neck mass assessment. The patient was sent to an urgent care center a week ago for nasal congestion and a sore throat. The symptoms went away after a few days, but his parents noted a persistent bulge in his neck. The patient has no past medical issues and is fully immunized. Physical examination reveals that he is healthy and well-nourished. A somewhat sensitive 2-cm midline lump travels up as the patient swallows, according to a neck examination. Which of the following is the most likely source of the lesion in this patient?

A) Abnormal migration of neural crest cells
B) Cervical implantation of thymic tissue
C) Dilation of cervical lymphatic channels
D) Incomplete obliteration of a duct
E) Persistence of second branchial arch structures
F) Trapping of skin structures along embryonic fusion lines