上眼瞼Merkel細胞癌の1例

A case of Merkel cell carcinoma on the upper eyelid

要約　目的：上眼瞼Merkel細胞癌の症例について報告する。

症例：83歳，男性。

所見：左上眼瞼の腫瘤を主訴に来院した。細隙灯顕微鏡検査では，左上眼瞼に8×9mm大の赤色調の球状腫瘤を認めた。急速に増大したためMerkel細胞癌を疑い，初診から6日後に左上眼瞼悪性腫瘍拡大切除術を施行した。腫瘍辺縁から5mmのsafety marginをとって拡大切除を行い，術中迅速病理診断で断端の腫瘍細胞が陰性であることを確認した。その後，switch flap法を用いて欠損した眼瞼を再建した。免疫組織学的検査の結果はMerkel細胞癌であった。術翌日に抗凝固薬を再開したところ，創部より多量の出血を認めたため，術後5日目および6日目に止血術を行った。2か月後に同部位に再び腫瘤を認めたが，切除したところ化膿性肉芽腫の診断で再発ではなかった。

結論：上眼瞼のMerkel細胞癌を経験した。術後に再度腫瘤を認めたが，再発ではなかった。ただし，再発しやすい腫瘍であるため，今後も慎重な経過観察が必要である。

Abstract　Purpose：To report a case of Merkel cell carcinoma on the upper eyelid.

Case：An 83-year-old man. He presented with a red-colored tumor on his left upper eyelid. The size of the tumor was 8×9 mm. Merkel cell carcinoma was suspected due to rapid growth. It was judged that early extended resection was necessary. Six days after the initial visit, tumor resection was performed from the upper eyelid. Extended resection of the tumor was carried out along a 5 mm safety margin, and negative margins were confirmed by intraoperative rapid histopathology. The skin defect was reconstructed with a switch flap from the lower eyelid. The pathological diagnosis was Merkel cell carcinoma. When the anticoagulant was restarted the day after the operation, a large amount of bleeding was observed from the wound, so hemostasis was performed on the 5th and 6th days after the operation. Two months later, a tumor was found again at the same site. However, the biopsied tissue was found to be pyogenic granuloma, with no recurrence.

Conclusion：We experienced a case of Merkel cell carcinoma of the upper eyelid. A tumor was found again after the operation, but it was not a recurrence. However, the tumor is likely to recur, so careful follow-up is required in the future.