乳児に生じ急速に増大した結膜皮様囊腫の1例

Dermoid cyst of the palpebral conjunctiva with rapid growth in an infant

要約　目的：乳児の瞼結膜に生じ，急速に増大した皮様囊腫の報告。症例：生後6か月の女児が左眼の腫瘤で受診した。腫瘤は出生時からあり，2か月前から急速に大きくなったという。腫瘤は眼球を覆い，磁気共鳴画像検査（MRI）では下瞼結膜からの囊胞で，眼球を上右側に圧排し直径が約20mmであった。手術中の所見として腫瘤が囊胞であることが確認され，病理学的に皮様囊腫と診断された。以後10か月間に再発はない。結論：皮様囊腫が乳児の眼部に生じることは稀ではないが，本症例は，これが眼球の下鼻側に生じ急速に増大したことで注目される。

Abstract.　Purpose：To report an infant with dermoid cyst in the palpebral conjunctiva. Case：A 6-month-old female infant was referred to us for a tumor in her left eye. The tumor had been present since birth and had started to enlarge rapidly since 2 months before. The tumor covered the left eyeglobe. By magnetic resonance imaging（MRI）, it appeared as a cyst that originated from the lower palpebral conjunctiva, displaced the eyeglobe towards upper-right direction, and was 20mm in diameter. During surgery, the tumor was found to be a cyst. Histopathological studies led to the diagnosis of dermoid cyst. There has been no relapse for 10 months until present. Conclusion：The present case illustrates that dermoid cyst may be located infero-nasal to the eyeglobe, that it may originate from lower palpebral conjunctiva, and that it may enlarge rapidly after birth.