Conversion surgery after BRAF-directed therapy for unresectable papillary thyroid carcinoma with severe tracheal invasion.

Locally advanced papillary thyroid carcinoma (PTC) with invasion of the airway and major vessels presents a significant therapeutic challenge. Although multikinase inhibitors (mTKIs) are effective for unresectable thyroid carcinoma, their antiangiogenic effects may increase the risk of life-threatening hemorrhage in patients with major vessel invasion or intraluminal airway exposure. Recent advances in BRAF-directed therapy have suggested a potential role for conversion surgery in selected patients with advanced thyroid carcinoma. A 75-year-old man presented with PTC with extensive intraluminal tracheal invasion causing severe airway stenosis, suspected common carotid artery involvement, and pulmonary metastases. The tumor was considered initially unresectable, and lenvatinib was avoided because of the risk of hemorrhagic complications. Following identification of a BRAF V600E mutation, treatment with dabrafenib plus trametinib was initiated. Dyspnea and wheezing resolved rapidly, and computed tomography demonstrated improvement of airway stenosis and restoration of a clear tissue plane between the metastatic lymph node and common carotid artery. Conversion surgery consisting of total thyroidectomy, circumferential tracheal resection, and bilateral neck dissection was subsequently performed. The postoperative course was uneventful. BRAF-directed therapy may represent a useful strategy for achieving conversion surgery in selected patients with locally advanced PTC.