喉頭平滑筋肉腫の1例

Leiomyosarcoma of the Larynx

I．はじめに

　喉頭悪性腫瘍のほとんどが扁平上皮癌であり，肉腫の発生率は癌腫の1％以下といわれている^1）。とりわけ平滑筋肉腫は稀であり，本邦では十数例の報告をみるに過ぎない。

　今回われわれは，喉頭平滑筋肉腫の1例を経験し，興味深い病理組織所見が得られたので，若干の文献的考察を加えて報告する。

　A 58-year-old man complained of hoarseness and presented with a supraglottic laryngeal tumor.

　Total laryngectomy was performed and the pathological findings by means of immunohistological methods revealed leiomyosarcoma of the larynx,because the tumor was positive for SMA（smooth muscle actin） and vimentin. At the stalk of the tumor,the severe dysplasia like squamous cell carcinoma was present instead of absence of the sarcomatous cells. The fact indicated that the present leiomyosarcoma did not necessarily originate in smooth muscle tissue and that it might be the result of dedifferentiation or disdifferentiation from the dysplasia of the laryngeal mucosa.