耳下腺筋上皮癌の1例

A case of myoepithelial carcinoma in the parotid gland

Ⅰ　はじめに

　筋上皮細胞は唾液腺，乳腺，前立腺，涙腺などの外分泌腺に存在し，上皮と平滑筋の両者の性格を併せもつとされている^1）。唾液腺に発生する筋上皮腫は唾液腺腫瘍の約1％と頻度の低い腫瘍であるが^1～3），筋上皮癌の頻度はさらに低い^4～6）。今回われわれは耳下腺に発生した筋上皮癌を経験したので若干の文献的考察を加えて報告する。

　Myoepithelial Carcinoma is a very rare tumor.

　A 65-year-old man with a right neck mass was referred to our hospital. On MRI,T2-weighted images revealed a high intensity mass. CT scan imaging revealed a mass in the right parotid gland. Echo-guided fine needle aspiration cytology was suspicious. Partial parotidectomy with the facial nerve preservation was performed. Pathologically,the tumor was diagnosed as myoepithelial carcinoma. He showed local recurrence 3 months after the first operation and total parodidectomy with resection of the facial nerve was done. Post-operative radiation was added. But he showed local recurrence and brain metastasis and died 5 months after the second operation.