上皮性涙腺腫瘍の6例

Six cases of epithelial tumor of the lacrimal gland

　上皮性涙腺腫瘍6例（良性4例，悪性2例）のCTおよびMRI所見を基に，良性と悪性の鑑別点を検討した。CT所見として，良性腫瘍では，腫瘍の辺縁に沿った平滑なbone erosion （菲薄化）を認めたのに対し，悪性腫瘍では辺縁の不整な骨破壊像を認めた。MRI所見では腫瘍の輪郭は良性腫瘍が円形，楕円形を示したのに対し，悪性腫瘍は凹凸のある不整な輪郭を示した。MRIにおける腫瘍の信号強度では明らかな相違はみられなかった。画像上における腫瘍の形状と隣接する骨所見は，上皮性涙腺腫瘍の良性と悪性の鑑別に有用な所見であると思われた。

We reviewed six cases of primary epithelial tumor of the lacrimal gland during the past 4 years. Four were benign and two were malignant. Computed tomography showed smooth bone erosion along the edge of a round mass in benign tumors and irregular bone destruction in malignant tumors. By magnetic resonance imaging (MRI) , the tumor mass appeared as round or oval in benign cases and as irregularly shaped in malignant cases. The signal intensity by MRI was the same for benign and malignant tumors. Above characteristic features by computed tomography and MRI are of value in differentiating benign and malignant epithelial tumors of the lacrimal gland.