太田母斑に合併した脈絡膜悪性黒色腫の1例

Choroidal malignant melanoma in a case of nevus of Ota

要約　目的：太田母斑に併発した脈絡膜悪性黒色腫の1例の報告。症例：71歳の女性が1か月前からの左眼の視力低下で紹介受診した。幼児期から左眼周囲の皮膚に色素沈着があった。所見と経過：矯正視力は右1.2，左0.02で，左眼周囲の皮膚に青褐色の色素沈着と強膜の色素沈着があった。左眼は浅前房で，脈絡膜腫瘤があった。PET-CTで左眼に集積像があり，MRIのT1強調画像で高信号，T2強調画像で低信号であった。5-S-CDが25.2nmol/lと上昇し，脈絡膜悪性黒色腫が疑われた。眼球摘出術が行われ，病理学的に太田母斑に合併した脈絡膜黒色腫と診断された。強膜にはメラニンを有する母斑細胞のみがあり，腫瘍細胞はなかった。初診の4か月後に転移性肝腫瘍で患者は死亡した。結論：太田母斑に脈絡膜悪性黒色腫が発症した稀有な症例である。

Abstract.　Purpose：To report choroidal malignant melanoma in a case of nevus of Ota. Case：A 71-year-old female presented with impaired visual acuity in the left eye since one month before. She had had pigmentation around her left eye since childhood. Findings and Clinical Course：Corrected visual acuity was 1.2 right and 0.02 left. She showed bluish-brown pigmentation around her left eye and pigmentation in the left sclera. The left eye showed shallow anterior chamber and choroidal tumor. PET-CT showed elevated signal by T1-enhanced image and low signal by T2-enhanced image. 5-S-CD in the blood was elevated to 25.2 nmol/l, leading to the diagnosis of choroidal malignancy. Enucleated eyeglobe was diagnosed with choroidal malignant melanoma associated with nevus of Ota. The sclera showed nevus cells containing melanine and no malignancy. The patient deceased 4 months after her initial visit due to metastatic hepatic tumor. Conclusion：This case illustrates that choroidal malignant melanoma may develop in an eye with nevus of Ota.