涙囊悪性黒色腫に対して拡大切除術後に免疫チェックポイント阻害薬を施行した1例

A Case of Lacrimal Sac Malignant Melanoma Treated with Immune Checkpoint Inhibitors after Wide Resection

はじめに

　涙囊原発悪性黒色腫は1926年に初めて報告され 1），ここ100年間で65例ほどの報告しかないとてもまれな疾患である 2）。また，平均生存期間が18カ月といわれており，予後不良な疾患である 3）。今回，涙囊悪性黒色腫の拡大切除術後に補助療法として免疫チェックポイント阻害薬を用いた症例を経験したので，若干の考察を含めて報告する。

　We report a case of lacrimal sac malignant melanoma treated with immune checkpoint inhibitors after wide resection. The patient was a 74-year-old man who had been aware of lacrimation in his right eye for three years but had neglected it. He was referred to our department for surgery in September of 2021 by the local plastic surgeon. At the first visit, an 18 × 7 mm subcutaneous induration was palpable in the right medial canthus. A surgical scar was found at the time of biopsy in the center of the induration. The injection of physiological saline from the punctum caused reflux, but no bloody reflux was observed. Lacrimal duct endoscopy showed no tumor in the lacrimal sac and cicatricial obstruction of the nasolacrimal duct. No abnormalities were observed in the nasal cavity or in the anterior segment of the eye. Five weeks after the patientʼs first visit to our department, the surrounding tissue including the lacrimal apparatus was resected. A glabellar flap and a malar flap were used for skin defects in the medial canthus. Intraoperative rapid pathology and permanent specimens were all negative for the margins, and the diagnosis was lacrimal sac malignant melanoma. Nivolumab was administered 8 times beginning 1 month after surgery, but since metastasis to the right lobe of the liver was later observed, combination therapy with nivolumab and ipilimumab was started at 9 months after surgery. After the second combination therapy, general malaise, fever, erythema, liver damage, autoimmune pancreatitis, interstitial pneumonia, and adrenal insufficiency were observed. After 4 doses of combination therapy, treatment with nivolumab alone was resumed and the patientʼs side effects improved. Continuation of ipilimumab was difficult due to its high toxicity. One year and seven months after the operation, the patientʼs condition is stable. Adjuvant therapy with nivolumab, which is known to be useful for mucosal melanoma, may also be effective for lacrimal sac melanoma. An accumulation of cases is needed.