A case of bilateral intrathyroidal branchial cleft cyst in a newborn.

We describe an extremely rare case of bilateral intrathyroidal branchial cleft cysts. A 2-day-old male neonate presented with intermittent tachypnea, dyspnea, and a palpable neck mass. Cervical ultrasonography and computerized tomography scan demonstrated a right-sided 3 x 3-cm cystic mass and a left sided 4.5 x 4-cm cystic mass, thought to be originating in the thyroid gland. The right-sided cyst decreased in size after OK-432 sclerotherapy. The left-sided cyst showed little response to 2 attempts of OK-432 sclerotherapy. Surgical removal of the left-sided cyst was done because of intermittent airway problems. The cystic mass was thought to be an intrathyroidal lesion. Microscopically, the cyst was lined by nonkeratinized squamous epithelium and respiratory epithelium. Lymphocyte infiltration was found in the subepithelial layer. The patient is currently doing well 12 months later with no evidence of recurrence.