Neck masses in children — branching viva

Opening

Examiner: A 4-year-old is brought in with a three-week history of a small, soft, tender lump under the angle of the jaw, just after a cold. How do you approach this, and what is your differential? ^[2]

Candidate: This is most likely a reactive viral lymph node, which is the commonest cause of cervical lymphadenopathy in children — cervical nodes are palpable in up to ninety per cent of children aged four to eight years. The features that support a benign reactive node are the preceding viral illness, the tender, soft, mobile character, the submandibular or anterior-triangle location, and the short three-week history. My approach is to take a focused history for red flags (weight loss, night sweats, fever, tuberculosis or animal contact) and examine the node's size, consistency, fixation and the other node groups. If it is a straightforward reactive node in a well child, I would reassure the family and give a clear safety-net to return at four to six weeks if the node has not resolved, or earlier if it enlarges or the child becomes unwell. ^{[2] [1]}

Branch 1 — the congenital midline mass

Examiner: A different child: a 6-year-old with a painless midline lump at the level of the hyoid that the mother says moves when the child swallows. What is this, and how do you confirm it at the bedside? ^[3]

Candidate: This is most likely a thyroglossal duct cyst, the commonest congenital midline neck mass. It arises from a remnant of the thyroglossal duct, the tract along which the thyroid descends from the foramen caecum to its pretracheal position, and because that tract passes through the hyoid bone the cyst moves upward when the child protrudes the tongue and when the child swallows. That is the bedside manoeuvre that distinguishes it from a dermoid cyst (which is more superficial and does not move) or a thyroid nodule (which moves only with swallowing). I would request an ultrasound to confirm the cystic lesion and to locate a normally positioned thyroid gland, and check thyroid function tests, because the cyst can rarely contain the only functioning thyroid tissue. ^[3]