耳下腺粘表皮癌と判明した原発不明頸部転移癌症例

A Case of Mucoepidermoid Carcinoma of the Parotid Gland

　はじめに

　粘表皮癌は主に唾液腺にみられる上皮性悪性腫瘍で，様々な分化度を示し，臨床上高分化型（低悪性）から低分化型（高悪性）まで存在する。このうち悪性度の高いものは扁平上皮成分が多く，扁平上皮癌と組織学的に鑑別が困難な場合がある。

　今回われわれは，原発不明の頸部転移性扁平上皮癌として初回治療を行い，その後耳下腺部に出現した腫瘍が高悪性度の粘表皮癌であった1例を経験したので，若干の文献的考察を加え報告する。

A 63-year-old woman complained of a mass in the right neck. By fine needle aspiration biopsy, the pathological diagnosis was lymph node metastasisof squamous cell carcinoma. We couldn't find the primary lesion, but we treated her with radical neck dissection.

Six months after the first operation, recurrent carcinoma appeared at the right pre-auricular region. A subtotal parotidectomy was performed and histpathological diagnosis was high-grade mucoepidermoid carcinoma of the parotid gland. It was suggested that the cervical lymph nodes resect-ed at the first operation was metastasis of muco-epidermoid carcinoma of the parotid gland.