眼窩内血管平滑筋腫の1手術例

A Case of an Orbital Angioleiomyoma

Ⅰ．はじめに

　血管平滑筋腫（angioleiomyoma, or vascular leiomyoma）は，平滑筋が存在する全身のあらゆる部位に発生する良性腫瘍であり，主として下肢に発生するが，頭頚部領域での発生は少ない．今回われわれは，眼窩内に発生した血管平滑筋腫の1例を経験したため，文献的考察を加えて報告する．

　A 70-year-old woman presented with a 4-year history of painless conjunctival congestion and proptosis of the right eye. Computed tomography and magnetic resonance imaging revealed a 48-mm lesion in the right medial orbit. As the symptoms progressed, the tumor was resected by performing fronto-orbital craniotomy. Histopathological examination revealed a vascular tumor surrounded by smooth muscle fibers and immunohistochemistry demonstrated tumor positivity for smooth muscle actin and desmin. The tumor was diagnosed as an angioleiomyoma, and no recurrence has been observed as of 5 years postoperatively. Angioleiomyomas in the orbit are extremely rare;thus, we have reported this case with reference to the literature.