Epidermal inclusion cyst of the thyroid: a rare case of a nodule-like structure at ultrasound.

An epidermal/(epi)dermoid cyst of the thyroid is a rare cause of an intrathyroidal mass. At radiological evaluation, it may initially be misinterpreted as a thyroid adenoma or carcinoma. We present a case report of a 15-year-old boy, who was evaluated because of a neck mass which caused globus pharyngeus and pain at swallowing. Ultrasound examination revealed a hypoechoic nodule-like structure in the left thyroid lobe. Aspiration of the nodule yielded white fluid. Cytological evaluation confirmed the diagnosis of an epidermal inclusion cyst of the thyroid.