甲状腺乳頭癌からの甲状腺未分化癌の喉頭蓋転移に対する経口ビデオ喉頭手術

We report an extremely rare case of hypopharyngeal metastasis with anaplastic transformation (anaplastic thyroid carcinoma) originating from papillary thyroid carcinoma, demonstrating successful tumor control using minimally invasive transoral surgery combined with targeted therapy. A 78-year-old man with a history of papillary thyroid carcinoma treated with total thyroidectomy and radioactive iodine 10 years earlier presented with sore throat and difficulty swallowing. Fiberoptic examination revealed a 25-mm mass on the posterior hypopharyngeal wall causing airway compromise, necessitating an emergency tracheotomy. Biopsy confirmed hypopharyngeal metastasis with anaplastic thyroid carcinoma. Given his comorbidities (chronic leukemia, severe pulmonary arterial hypertension), he underwent transoral videolaryngoscopic surgery to achieve local tumor control while preserving swallowing function. Postoperative genetic testing detected a BRAF V600E pathogenic variant, leading to treatment with encorafenib and binimetinib, initiated on postoperative day 24. Six months after surgery and targeted therapy, fiberoptic examination and contrast-enhanced computed tomography showed no evidence of recurrent disease; the tracheostomy was closed, and the patient maintained normal swallowing and quality of life. This case illustrates that a surgery-first, function-preserving approach integrated with early molecular-targeted BRAF/MEK inhibition can achieve durable local control and maintain laryngopharyngeal function, even when anaplastic transformation occurs within a hypopharyngeal metastatic focus.