両結膜生検を契機に診断されたstage Ⅳ MALTリンパ腫の1例

A case of clinical stage Ⅳ MALT lymphoma diagnosed by conjunctival biopsy

要約　目的：結膜生検を契機に診断されたstage Ⅳ MALTリンパ腫の1例を報告する。

症例：77歳，女性。左眼の異物感を主訴に近医を受診し，左上眼瞼腫瘍を指摘された。抗菌薬，ステロイド点眼で治療されたが，改善しなかったため通院を自己中断した。1年後に異物感の悪化を主訴に近医を再診し，腫瘍の増大を指摘され，精査目的に当院を紹介受診した。

所見：左上眼瞼翻転部および両円蓋部結膜にサーモンピンク色の隆起性病変を認めた。結膜生検と免疫染色にてMALTリンパ腫と診断された。PET/CTにて横隔膜を挟んだ上下のリンパ節，上咽頭，肺，骨への集積を認めた。リンパ節および骨髄生検にてMALTリンパ腫の浸潤を認め，Ann Arbor分類でstage ⅣのMALTリンパ腫と診断された。化学療法の開始以降はリンパ節病変は縮小し，再発を認めていない。また結膜腫瘍も再発を認めていない。

結論：MALTリンパ腫は通常限局性で，眼付属器発症例における進行例は10％程度とされており，多臓器転移がみられた本症例は稀といえる。また本症例は結膜生検が血液疾患の診断確定および治療方針決定に寄与した症例であり，未診断の全身疾患の診断確定における眼付属器生検の有用性を示唆している。

Abstract　Purpose：To report a case of clinical stage Ⅳ mucosa-associated lymphoid tissue（MALT） lymphoma diagnosed by conjunctival biopsy.

Case：A 77-year-old female referred to our hospital for further evaluation of a left upper eyelid tumor. One year prior to the initial visit, the patient presented at a local clinic with a sensation of a foreign body in her left eye and was noted to have an upper eyelid mass. Despite the treatment with topical antibiotics and steroids, no improvement was observed, and follow-up was discontinued at the patient's own discretion. After one year, the patient returned to the local clinic with a worsening of the foreign body sensation and was referred to our hospital for further evaluation.

Findings：A salmon-pink, elevated lesion was observed in the superior tarsal and fornix conjunctiva. Conjunctival biopsy and immunohistochemistry confirmed the diagnosis of MALT lymphoma. A PET-CT scan revealed abnormal uptake in the lymph nodes both above and below the diaphragm, the nasopharynx, the lung, and the bone. Lymph node and bone marrow biopsies revealed infiltration of MALT lymphoma, and the disease was diagnosed as Ann Arbor stage Ⅳ. Following the initiation of chemotherapy, the lymph node lesions showed a tendency to shrink, with no indication of recurrence. The conjunctival lesion has also remained recurrence-free.

Conclusion：MALT lymphoma typically presents as a localized disease, and advanced cases in the ocular adnexa are reported in approximately 10％ of patients. Therefore, this case with multi-organ involvement represents a rare presentation. Furthermore, it highlights the diagnostic value of conjunctival biopsy, not only for confirming hematologic malignancy but also for establishing the diagnosis and treatment strategy of previously undiagnosed systemic disease.