CTスキャンにより診断されたtrilateral retinoblastoma三側性網膜芽細胞腫の症例

A case of presumed trilateral retinoblastoma diagnosed by computed tomography

　両眼性網膜芽細胞腫に松果体腫瘍を合併した1例を経験した．症例は9カ月の女児で左眼の白色瞳孔を主訴として来院し，左眼は腫瘍が眼内に充満し，眼球摘出によって組織学的に網膜芽細胞腫であることが確認された．右眼は網膜後極部に5乳頭径の腫瘤1個，赤道部に1乳頭径の腫瘤2個が見られる多中心性腫瘍であり，保存療法（放射線療法，光凝固療法）を行って瘢痕化に成功している．脳CTにて松果体領域に異常な石灰沈着とenhancementにより増強される松果体腫瘍と思われる病変を認めた．松果体腫瘍には放射線療法を行い，増大を見ずに1年間経過観察中である．右眼および全身的に他の再発転移の徴候はなく松果体腫瘍は松果体原発のものと思われた．松果体腫瘍の組織学的証明はないが，臨床的に本症は両眼の網膜芽細胞腫に松果体腫瘍を合併したtrilateral retinoblastoma三側性網膜芽細胞腫と診断され，きわめて珍しい症例であった．本症の診断には脳CTが必須の検査であり，両眼性網膜芽細胞腫患者をみたとき，ならびに経過観察中には両者の合併に注意すべきである．

We observed a case of bilateral retinoblastoma as-sociated with pineal tumor. A 9-month-old female child had manifested leukokoria in her left eye since 2 months before. The left eye was affected by total retinal detachment with opaque subretinal mass. In the right eye, we detected three white retinal masses. We diagnosed multicentric bilateral retinoblastoma. The left eye was enucleated and the right eye was success-fully treated by xenon photocoagulation and cobalt 60 therapy.

Computed tomography of the skull revealed abnor-mal calcification and swelling of the pineal body. This lesion was well enhanced by contrast material. Pathol-ogical studies of the enucleated left eye showed well-differentiated retinoblastoma without signs of invasion into the choroid, optic nerve, or the orbit. The pineal lesion was treated with cobalt 60 therapy totalling 3,000 rads with apparent success, as the pineal tumor ceased to enlarge thereafter. Lacking evidence of systemic metastasis of tumor in the present case, we suspected the pineal tumor to be of primary origin. Although no histological features of the pineal tumor were clarified, we diagnosed this case as presumed trilateral retino-blastoma. We also recommend screening all cases of bilateral retinoblastoma with computed tomography as a routine procedure.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(10) : 1157-1161, 1986