ベバシズマブ硝子体内注射と光線力学的療法の併用療法が奏効した漿液性網膜剝離を伴う脈絡膜骨腫の1例

A case of choroidal osteoma treated by photodynamic therapy and intravitreal bevacizumab injection

要約　目的：脈絡膜骨腫は，脈絡膜に発生する良性腫瘍で，漿液性網膜剝離（SRD）や脈絡膜新生血管（CNV）を生じ，症例によっては視力予後が不良である。脈絡膜骨腫に続発したSRDに対してベバシズマブ硝子体内注射（IVB）と光線力学的療法（PDT）の併用療法が奏効した症例を報告する。

症例：47歳の男性が，右眼の歪視と視力低下を自覚し受診した。

所見：右眼矯正視力は1.0で，黄斑部を含まない右眼視神経乳頭近傍に色素沈着のある黄白色隆起病変を認めた。眼底造影検査でCNVは認められなかった。Bモードエコーで音響陰影を伴う高反射病変を認め，CTで高吸収領域を眼球後壁に認めたため脈絡膜骨腫と診断した。黄斑部にSRDを認めたため，IVBを4回施行し，SRDはわずかに減少した。しかし，腫瘍は拡大傾向を認めたため，ベルテポルフィン（3mg/m²体表面積）投与下でのreduced fluence PDTを施行した。しかしSRDが残存したため，IVBとベルテポルフィン（6mg/m²体表面積）投与下でのstandard PDTの併用療法を施行し，SRDは消失し，視力も改善した。最終治療1年後，視力は安定しSRDの再発はない。

結論：CNVを伴わず，SRDを合併した脈絡膜骨腫において，IVBの効果が認められない場合には，IVBとPDTの併用療法が有効である可能性がある。

Abstract　Purpose：Although choroidal osteoma（CO）is a benign tumor within the choroid, vision may be compromised by serous retinal detachment（SRD）and choroidal neovascularization（CNV）. We report a case of CO accompanied by SRD that showed favorable visual and anatomical outcomes after combination of photodynamic therapy（PDT）and intravitreal bevacizumab injection（IVB）.

Case：A 47-year-old man was referred to us with decreased visual acuity and anorthopia in his right eye.

Findings：Best-corrected visual acuity（BCVA）was 1.0 in the right eye at his first hospital visit. The right eye showed a whitish-yellow elevated subretinal lesion with overlying pigmentary changes in the juxtapapillary regions and without involving the macula. Fluorescein and indocyanine green angiographies revealed no CNV. B-scan ultrasonography indicated a choroidal mass of high reflectivity and acoustic shadowing. Computed tomography（CT）additionally showed dense choroidal plaque, thereby leading to the diagnosis of CO. As optical coherence tomography revealed SRD in the macula, the patient underwent four sessions of IVB. However, there was almost no improvement of the SRD. Due to extension of this mass, we then performed reduced-fluence PDT. As this also had little effect, we subsequently performed a standard PDT combined with IVB, which led to remarkable improvement of the BCVA and SRD. There has been no recurrence of SRF in the one year since treatment, with the BCVA remaining stable.

Conclusion：PDT combined with IVB might be an effective therapy for CO accompanied by SRD and without CNV, for which IVB alone does not have any effect.