[Pleural Dissemination of Papillary Thyroid Carcinoma:Report of a Case]

A 67-year-old man was performed total thyroidectomy for stage ⅣC papillary thyroid carcinoma with multiple lymph node and lung metastases. Five years and two months later, treatment with lenvatinib was started. Chest computed tomography (CT) six years and four months after the start of treatment revealed left pleural effusion. A pleural biopsy was performed under thoracoscopy. Histopathological findings showed papillary thyroid carcinoma, and the patient was diagnosed with pleural dissemination of thyroid cancer. Genetic test showed a positive BRAF V600E gene mutation. Treatment with dabrafenib and trametinib was initiated nine days after lenvatinib was discontinued.