耳下腺腺房細胞癌の1症例—その診断と治療方針

A Case of Acinic Cell Carcinoma of the Parotid Gland: Its Diagnosis and Planning for Therapy

　はじめに

　耳下腺腺房細胞癌は，耳下腺悪性腫瘍の十数％を占めるものの^1,2），耳下腺腫瘍症例が多い施設でも5年に1例経験する程度の稀な腫瘍であるため，その治療に困難を感じることが少なくない。しかも，耳下腺ではその中に顔面神経が貫通しているため，その処理が最も問題となる。また，腺房細胞癌は一般に悪性度が低く，症状の進行が緩慢であるため，良性腫瘍として手術が施行されることがある。

　今回われわれは，耳下腺腺房細胞癌症例を経験したので，症例を報告するとともに，その診断と手術方針について考察した。

A 64-year-old male was complaining of a mass at the pre-auricular region without pain and facial palsy. Histopathological type of the parotid mass was not able to diagnose by fine needle aspiration biopsy and other examinations before operation. After superficial lobectomy of the parotid gland, the mass was examined by frozen section pathology, which showed acinic cell carcinoma, then we addedsupra-omohyoid neck dissection. Though acinic cell carcinoma was thought to be low-grade malig-nancy, its long-term survival rate is not always good because of local recurrence. Many authors supported that the treatment for this tumor was at least wide excision with clear surgical margins. Therefore, in case involving the facial nerve, the tumor should be excised to sacrifice the nerve with clear surgical margins.

Therefore, preoperative histopathogical diagnosis of the tumor was essential for an appropriate opera-tion. Because the results of fine needle aspiration biopsy and frozen section biopsy in the parotid cancer was not confirmative, open biopsy should be performed positively for accurate histological diag-nosis to improve their prognosis.