網膜芽細胞腫治療後にみられた二次腫瘍の2例

Two cases of second tumor following treatment for retinoblastoma

　網膜芽細胞腫治療後の二次腫瘍の2例を経験した。1例は女児で，生後6か月に両眼性網膜芽細胞腫と診断され，左眼摘出と，右眼に光凝固，化学療法，総線量40Gyの放射線照射を受け治癒した。13年後に副鼻腔に悪性線維性組織球腫が発生し，手術と放射線療法で治癒した。他の1例は男児で，生後3か月に両眼性網膜芽細胞腫と診断され，左眼摘出と，右眼に光凝固，化学療法，総線量38Gyの放射線照射を受け治癒した。11年後に髄膜腫が発症し，手術で治癒した。2例とも以後再発はない。両症例とも放射線療法を受け，照射野に二次腫瘍が発症したが，放射線照射の影響とともに遺伝的な素因が関係している可能性がある。

A 6-month-old female infant was diagnosed with bilateral retinoblastoma. Her left eye was enucleated.The right eye cured after photocoagulation, chemotherapy and irradiation totalling 40 Gy. Malignant fibrous histiocytoma developed in the left antrum 13 years later. It was successfully treated by surgical removal and irradiation. Another 3-month-old male infant was diagnosed with bilatelral retinoblastoma. His left eye was enucleated. The right eye cured after photocoagulation, chemotherapy and irradiation totalling 38 Gy. Meningioma developed 11 years later and was successfully treated by surgery. There has been no recurrence in both cases. The second tumor in both cases developed in irradiated areas. There is a possibility that irradiation as well as genetic factors may have been involved in its occurrence.