甲状腺腫瘍との鑑別が困難であった頸部異所性胸腺腫の1例

Ectopic Cervical Thymoma that was Difficult to Differentiate from Thyroid Tumor：Report of a Case

はじめに　異所性胸腺腫は異所性胸腺に発生するまれな腫瘍と考えられており，1941年にはじめて報告された1）．術前診断は困難で，切除標本による病理組織検査で確定診断されることが多い．また，頸部に発生した場合は甲状腺腫瘍との鑑別が問題となる．われわれは，術前・術中診断が困難であった頸部異所性胸腺腫を経験したので，文献的考察を加えて報告する．

We report a case of ectopic cervical thymoma that was difficult to differentiate from thyroid tumor. A 69-year-old woman was referred to our hospital with a tumor on the left side of the neck. Fine-needle aspiration cytology could not establish the diagnosis and the surgery was then performed for diagnosis and treatment. Since the intraoperative pathological diagnosis was also inconclusive, thymectomy was performed because of the macroscopic finding suggesting close relation to the thymus. The final pathological diagnosis was type AB thymoma.