An unusual dermoid cyst of the neck presenting as mass in the lateral neck

Abstract

Cystic lesions in the neck are common. It is customary to classify them as those arising in the midline and those in the lateral neck. Dermoid cysts are present along the lines of embryonic fusion and hence said to be occurring due to an embryonic accident during the development. Most common locations in the neck are the lateral end of eyebrows and the floor of the mouth in the midline. We present a rare case of dermoid presenting as a mass in the lateral aspect of neck. Our case is unique since even though it was a dermoid cyst, the presentation of the mass was in the upper lateral neck which is very uncommon. A 28-year-old lady presented with a swelling at the junction of the upper one-third and lower two-third of the left sternocleidomastoid muscle. Intraoperatively, the cyst had extension from the lateral aspect of neck along the carotid sheath to the superior mediastinum. Dermoid cysts do present occasionally as lateral neck mass and must be kept in the differential diagnosis. Even though characteristic radiological and histopathological features make the diagnosis of dermoid cyst simple yet it may be difficult to diagnose, if present at unusual locations.