Abstract
BACKGROUND: We present the case of a rare occurrence of an anterior mediastinal mature teratoma extending into the neck, commonly referred to as a cervicothoracic mature teratoma. CASE PRESENTATION: A 19-year-old female presented with right-sided neck pain and swelling, which were found to be attributed to a 14 cm cystic lesion originating from the right thyroid lobe and extending into the mediastinum. A diagnosis of mediastinal teratoma with extension to the neck was made. Robot-assisted thymectomy was initiated but was complicated by dense tumor adherence to the superior vena cava and brachiocephalic veins, prompting a switch to a midline sternotomy. Simultaneous resection of the right thyroid lobe was performed due to inflammation. The transition to a midline sternotomy allowed successful excision of the tumor, which was confirmed to be a mature teratoma confined to the thoracic region. The patient's favorable postoperative course led to discharge on day 5 with no recurrence at nine months. CONCLUSIONS: Emphasizing the challenges and the importance of prompt intervention in the management of mediastinal teratomas with neck extension.