結膜腫瘤を生じたIgG4関連眼疾患の1例

A case of IgG4-related ophthalmic disease involving the conjunctiva

要約　目的：結膜腫瘤を生じたIgG4関連眼疾患の1例の報告。

症例：当院初診時61歳の女性。好酸球性副鼻腔炎，気管支喘息にて治療中であった。

所見と経過：3か月前より右眼の腫瘤を自覚し，近医を受診した。精査・加療目的にて当院に紹介された。当院初診時，右上眼瞼の肥厚と結膜に充血を伴う腫瘤病変があった。眼窩部CT画像では右外直筋・下直筋と一塊になった涙腺腫大があり，血液検査では血清IgG4が高値であった。ステロイド点眼にて充血は軽減したものの腫瘤は縮小しなかったため，診断も兼ねて結膜病変を摘出し，病理検査を実施した。病理組織診断では形質細胞の浸潤を認め，IgG4陽性/IgG陽性細胞比は50％以上であった。悪性リンパ腫を疑う所見はなかった。臨床所見と病理所見から総合的にIgG4関連眼疾患と診断し，プレドニゾロン30mgから内服を開始した。開始から17か月時点で1mgまで減量したが，再発は認めていない。

結論：結膜腫瘤を生じたIgG4関連眼疾患の1例を経験した。ステロイド内服で涙腺と眼窩部病変は改善し，結膜病変も短期的には再発はなかった。

Abstract　Purpose：To report a case of conjunctival tumor in IgG4-related disease.

Case：The patient was a 61-year-old woman. She was diagnosed with asthma and eosinophilic sinusitis.

Findings and clinical courses：Three months ago, she became aware of a conjunctival tumor. A large mass was found in the upper right bulbar conjunctiva. Computed tomography demonstrated swelling of the right extraocular muscles and lacrimal gland. Serum IgG4 level was elevated. As this lesion did not improve with eye drop therapy, we performed a surgical resection. Histopathologically, there were no malignant findings. Plasmacytes were positive for IgG, and over 50％ of these cells were positive for IgG4. Based on these histopathological and serological findings, this case was diagnosed as an IgG4-related ophthalmic disease. Systemic administration of predonisolone was started. After the resection, there was no recurrence of the conjunctival mass for seventeen months.

Conclusion：We report a case of conjunctival tumor in an IgG4-related disease in which surgical resection was performed as it did not respond to eye drop therapy.