横行結腸癌原発の右眼転移性虹彩毛様体腫瘍の1例

A case of iridociliary tumor metastatic from carcinoma of transverse colon

要約　背景：悪性腫瘍の眼球への転移は，肺癌と乳癌の脈絡膜転移が多く，消化器癌の虹彩毛様体への転移は稀である。目的：結腸癌が虹彩毛様体に転移した1例の報告。症例：54歳女性が6週間前からの右眼の視朦と充血で受診した。5年前に横行結腸癌の切除手術を受け，すでに腹膜転移があった。以後，複数の抗癌剤による治療を受け，すでに肺，腹膜，Douglas窩を含める全身転移があった。所見：矯正視力は右0.2，左1.2で，眼圧は右12mmHg，左16mmHgであった。右眼虹彩の下方部位に3mm大の黄白色腫瘤があり，これに相当する毛様体に腫瘤の浸潤があった。眼痛がなく，積極的な治療は行わなかった。虹彩腫瘤は月に1mmの速さで増大したが，眼圧上昇はなかった。初診から50日後に全身状態が悪化し，不帰の転帰をとった。結論：悪性腫瘍の虹彩毛様体への転移は，増加する可能性がある。ぶどう膜炎と所見が類似することがあり，注意が必要である。

Abstract.　Purpose：To report a case of iridociliary tumor metastatic from carcinoma of transverse colon. Case：A 54-year-old woman presented with blurring and hyperemia in the right eye since 6 weeks before. She had received resection of transverse colon carcinoma 5 years before. Metastasis to the peritoneum was already present. She had been treated with multiple antineoplastic medications. Systemic metastases were present including the lung, peritoneum, and Douglas cavity. Findings：Corrected visual acuity was 0.2 right and 1.2 left. Intraocular pressure（IOP）was 12 mmHg right and 16 mmHg left. The right eye showed signs of anterior uveitis and an iris tumor. It was located in the inferior sector of the iris and was 3 mm in size. A similar tumor was present in the corresponding site of ciliary body. The tumor increased in size at the rate of 1mm per month. IOP stayed within normal range throughout. Death ensued 50 days after her initial visit. Conclusion：This case suggests that incidence of intraocular metastasis of malignant tumor may increase in time to come. Malignant tumor metastatic to the iris and ciliary body needs due attention in differentiating from uveitis.