Multilocular Cervical Thymic Cyst: Rare Cervical Lesion should kept in Mind in Differential Diagnosis of Pediatric Cervical Masses

Multilocular Cervical Thymic Cyst: Rare Cervical Lesion should kept in Mind in Differential Diagnosis of Pediatric Cervical Masses

Congenital anomalies are the most common causes of benign cystic neck masses during the childhood. Cervical thymic cyst is a rare and unique form of cystic neck mass which is usually seen in the first decade of life. Preoperative diagnosis of cervical thymic cysts is challenging due to the rarity and insignificant findings. A seven-year-old-boy presented to hospital with the complaint of progressive swelling on the right side of the neck over a year. Radiologically, magnetic resonance imaging (MRI) revealed a 95 × 37 × 30 mm in size cystic mass located at the right side, anterior of SCM which was related with the carotid sheath. Surgical resection was performed. In the childhood, the thymic cyst comprises less than 1% of the cervical cystic lesions. Rarely may they show malignant transformation. Unilocular thymic cysts are usually congenital and are thought to arise from cystic dilatation of branchial pouch remnants, whereas multilocular thymic cysts are considered to be acquired reactive lesions. Finally, cervical thymic cyst is very rare benign cystic neck mass during the childhood. However, it should be kept in mind in differential diagnosis in case of asymptomatic patients who are between the ages of 2-13 and total surgical resection should be performed because of malignant transformation potential.