Congenital cystic neck mass of thymic origin.

Neck masses are frequently seen in children. The differential diagnosis includes infectious, congenital and neoplastic lesions. We report a case of rare thymic neck mass in a boy in his middle childhood presented with a history of a left anterolateral neck mass not associated with fever, dysphagia or shortness of breath. The radiographic evaluation showed a picture of a thymopharyngeal duct cyst. Thymic remnant and thymopharyngeal duct cyst are caused by the failure of obliteration and might appear as a lateral neck mass in children. The most effective treatment for a thymopharyngeal duct cyst is total surgical excision. This particular case highlights the importance for clinicians to have a high index of suspicion for a broad differential diagnosis when evaluating paediatric patients who present with neck mass. Additionally, we emphasise the importance of consistently considering thymopharyngeal cyst as differential diagnosis.