片眼性の黄白色網膜病変から始まりサルコイドーシスと診断された1例

A case of sarcoidosis initially presenting with unilateral yellow-white retinal lesions

要約　目的：片眼性の黄白色網膜病変から始まり，診断に苦慮したサルコイドーシスの症例を報告する。

症例：69歳，女性。右眼の霧視を自覚し近医を受診したところ，片眼性の黄白色網膜病変があり，急性網膜壊死を疑い前医を紹介され受診となった。

所見と経過：視力は両眼とも（1.2）で，左眼に特に異常所見はなかった。右眼に黄白色病変と網膜出血，硝子体混濁があったため急性網膜壊死を疑い，アシクロビル点滴を開始した。アンジオテンシン変換酵素（ACE）の軽度上昇があり，呼吸器内科で精査したがサルコイドーシスは否定された。前房水PCR検査でもヘルペス属ウイルスなどはすべて陰性であった。感染性ぶどう膜炎は否定的と考え，プレドニゾロン内服治療を開始した。炎症は軽快したがプレドニゾロンを10mg/日以下にすると再燃を認めたために，白内障・硝子体同時手術を行い，硝子体生検も行ったが確定診断には至らなかった。発症から8か月経過しても炎症所見が持続したため名古屋大学医学部附属病院（当院）へ紹介となった。当院受診時に左眼底に結節性病変を認め，胸部CTで縦隔リンパ節の腫大があり，気管支鏡検査でサルコイドーシスと確定診断された。

結論：当初は片眼のみの非特異的な所見で，急性網膜壊死との鑑別に苦慮した。ぶどう膜炎は診断が困難な場合が多く，全身性疾患を念頭に置いて，他科と協力して慎重なフォローアップと精査の継続が必要であると示唆された。

Abstract　Purpose：To report a case of sarcoidosis that initially presented with unilateral yellow-white retinal lesions and posed considerable diagnostic challenges.

Case：A 69-year-old woman noticed blurred vision in her right eye and visited a local clinic. Fundus examination revealed unilateral yellow-white retinal lesions, and acute retinal necrosis（ARN） was suspected；she was therefore referred to a secondary hospital.

Findings and Clinical Course：At the initial visit, best-corrected visual acuity was 20/20 in both eyes, and no abnormalities were observed in the left eye. The right eye showed yellow-white retinal lesions, retinal hemorrhages, and vitreous opacities, leading to a working diagnosis of ARN and initiation of intravenous acyclovir. Laboratory testing revealed mildly elevated angiotensin-converting enzyme（ACE） levels, but respiratory evaluation did not support a diagnosis of sarcoidosis. Multiplex PCR of aqueous humor was negative for herpesviruses. Infectious uveitis was considered unlikely, and oral prednisolone therapy was initiated. Although the inflammation improved, it recurred whenever prednisolone was tapered below 10 mg/day. Combined cataract extraction and pars plana vitrectomy with vitreous biopsy were performed；however, no definitive diagnosis was obtained. Because ocular inflammation persisted for eight months after onset, the patient was referred to our hospital. At presentation, a nodular fundus lesion was identified in the left eye. Chest CT revealed mediastinal lymphadenopathy, and bronchoscopy subsequently confirmed sarcoidosis.

Conclusion：This case initially presented with nonspecific unilateral retinal lesions, making differentiation from ARN challenging. Uveitis can be difficult to diagnose, and this case highlights the importance of considering systemic diseases and maintaining close collaboration with other medical specialties, along with careful follow-up and continued diagnostic evaluation.