Successful resection of mediastinal spread thyroid carcinoma by median sternotomy. A case report

Background: Papillary thyroid carcinoma (PTC) represents the most frequent malignant thyroid neoplasm, with a generally indolent clinical course. Despite its good prognosis, it can present lymph node metastases, being those located in the mediastinum uncommon (6-12%), associated with advanced and recurrent disease. In these cases, a more aggressive surgical approach, such as median sternotomy, may be necessary to achieve a complete resection. Case presentation: A 45-year-old female patient with a history of cervical resection of tumor suspected of lymphangioma, whose histopathological study reported metastasis of papillary thyroid carcinoma. She was referred to our unit, where imaging studies showed lymph node conglomerates in the right neck with mediastinal extension. Total thyroidectomy was performed, modified radical dissection of the right neck and, due to the involvement of level VII, median sternotomy for resection of the lymph node conglomerate adhered to the trachea, esophagus, right vagus nerve and vascular structures (Figure 1 and 2). The dissection was performed safely without major complications. The histopathological study confirmed lymph node metastasis of PTC. The patient presented favorable evolution, with transient hypocalcemia as the only complication and no evidence of recurrence at six months. Discussion: Mediastinal metastases due to PTC require a high clinical suspicion and adequate imaging evaluation for their diagnosis. Although cervical lymphadenectomy is well established, mediastinal resection is infrequent and represents a surgical challenge due to its proximity to vital structures. Sternotomy allows wide and safe exposure in these selected cases, being a useful tool when the cervical approach is insufficient. Conclusion: Median sternotomy, although infrequent in thyroid surgery, may be indispensable to achieve complete resection of mediastinal metastases in advanced PTC, offering adequate oncologic control with acceptable morbidity. This case highlights the importance of a comprehensive preoperative evaluation and consideration of extended approaches in patients with advanced locoregional disease. Key words: papillary thyroid carcinoma, sternotomy, mediastinal tumor, lymph node metastasis.