Endocrine Abstracts

Introduction: Cervical thymic cysts are among the rarest congenital neck masses. Thymic migration into the superior mediastinum during organogenesis explains the topography and diversity of clinical presentations of these cysts. Due to the possibility of mediastinal extension, the management of these lesions is different than other congenital neck masses. The aim of our work is to present the clinical, radiological, and therapeutic features of cervicomediastinal thymic cysts.

Case report: A 13-year-old child was referred to our hospital for chronic cervical swelling. Clinical examination revealed a left basicervical mass. This mass was firm and painless. The rest of examination was without abnormalities. He did not have any neurological symptoms. Ultrasound and cervical Computed Tomography showed thyroid plunging from the lower pole of the left thyroid. On the surgical field, thyroid-independent cystic formation from the upper mediastinum with extension to the cervical region was found. A complete excision was performed after ligature and section of the lower cystic attachments. The anatomopathological examination diagnosed a thymic cyst with thymic parenchyma hyperplasia.

Conclusion: It’s very important to recognize a cervicomediastinal thymus cyst as a differential diagnosis of pediatric neck masses, such as cervical lymphadenopathy, branchial anomalies, vascular malformations, inflammatory lesions and neoplasm. Ultrasound and CT scan can help to establish the etiological diagnosis.