Successful recovery from a subclavicular ulcer caused by len
There are currently no effective therapeutic methods for locally recurrent, metastatic, or progressive radioactive iodine (RAI)-refractory differentiated thyroid cancer. However, multitargeted tyrosine kinase inhibitors (TKIs) such as lenvatinib or sorafenib have been approved for patients with RAI-refractory differentiated thyroid cancer as a second targeted therapy, and these agents can prolong patient survival. However, several cases have been reported that TKIs have caused fatal complications such as fistula formation or bleeding.

Case presentation
We report a case of a 53-year-old woman, who underwent repeated neck dissections and RAI therapy after total thyroidectomy in an outside hospital. Pathology revealed a papillary carcinoma of the tall cell variant. Locoregional recurrence was not under control; therefore, she visited our hospital. Although surgery was performed for locoregional recurrences three times in our hospital, they were not under control and distant metastases were found in the lung and bone a year later. Therefore, although sorafenib was initiated, the locoregional recurrence progressed 6 months later and computed tomography (CT) showed a 7-cm mass in the right subclavicular lesion. Lenvatinib was started at a dose of 24 mg daily. However, although tumor was rapidly reduced, an ulcer occurred in the right subclavicular lesion and was gradually increasing in size. The pulsation of subclavicular artery was found in the deep portion of the ulcer. Therefore, a pectoralis major myocutaneous flap was transplanted to cover the ulcer. Lenvatinib was an antiangiogetic TKI; therefore, it was preoperatively discontinued for 8 days and postoperatively for 12 days. The postoperative course was uneventful....