Unusual patterns of congenital neck masses in children

Congenital neck masses—thyroglossal duct cysts (TDC) and branchial cleft cysts (BCC)—are frequently encountered in any pediatric surgical practice. While their diagnosis is usually straightforward, unusual or combined presentations may occur. We report eleven cases of unusual patterns of congenital neck masses in children. Two patients underwent resection of a BCC with a sinus tract extending through the carotid bifurcation. Both patients subsequently presented with a new mass near the previous scar, which was thought to be a recurrence but was found at surgery to have TDCs with sinus tracts extending through the hyoid bone. In one patient, a lateral neck mass (presumed to be a BCC) was found at surgery to be a TDC. In all three cases the diagnoses were confirmed histologically. Eight patients presented with a solitary thyroid nodule. Six of these had intrathyroid branchial cleft remnants, and two had intrathyroid TDCs. The diagnosis became apparent at operation in six patients, while in two it was made by the pathologist after hemithyroidectomy. Ages at presentation ranged from 16 months to 14 years. The embryology of these neck structures is closely related. It should not come as a surprise that errors in their development may occur, at times paralleling the occurrence of intrathyroid location of parathyroid glands. The possibility of an embryologic rest in the neck should therefore be kept in mind with all clinically evident neck masses. TDCs and BCCs may coexist in the same patient. The histologic differentiation may be difficult in the presence of inflammation, but differences in structure are often characteristic. While it may not be possible to distinguish the intrathyroid lesions from primary thyroid masses preoperatively, it may be possible to limit the extent of resection once the diagnosis is reached. Such knowledge may greatly assist the surgeon at the time of operation.