眼窩原発横紋筋肉腫の1例

A case of alveolar type rhabdomyosarcoma of the orbit

　5歳女児の眼窩原発横紋筋肉腫（alveo-lar type）の1例について報告した。全身的に異常所見はなく，軽度の眼球突出と視力低下が初発症状で眼科を受診した。頭部CT検査で右眼窩鼻上側に腫瘍を認め，脳外科にて経頭蓋法で腫瘍摘出を行った。病理組織診断は通常の染色のみでは鑑別が大変困難で，免疫組織化学的検査でデスミンを使用して横紋筋肉腫と確定することができた。眼窩内容除去術は行わず，現在小児科にて化学療法剤で加療中である。横紋筋肉腫は本症例のようにひとつの治療法だけでは根治は難しく，各科が協力して治療を行う必要があると考えた。

A 5-year-old girl presented with slight exophth-almos and visual disturbance in her right eye. Computed tomography showed a mass lesion in the right nasal orbit. We resected the tumor by trans-cranial approach. Histopathological findings with routine hematoxylin and eosine staining were in-conclusive. We diagnosed the condition as rhab-domyosarcoma by immunohistochemical studies utilizing myogenous protein antibody. Postsurgical-ly, the patient was treated by systemic vincristine, actionomycin D and cyclophosphamide with favor-able clinical course. We advocate active coopera-tion of pathologist, pediatrician, brain surgeon, otolaryngologist and ophthalmologist in the diag-nosis and treatment of orbital rhabdomyosarcoma in children.