慢性涙囊炎として加療されていた涙囊部悪性腫瘍の1例

A case of malignant lacrimal sac tumor masquerading as chronic dacryocystitis

　72歳女性が15か月前に涙囊部に腫瘤が生じ，慢性涙囊炎として治療されていた。涙囊部に腫瘍が発見されて当科を受診した。右涙囊部と右耳前部に無痛性の腫瘤があり，画像診断で涙囊部腫瘍は篩骨洞に浸潤し，ガリウムシンチグラフィで同部位に集積があった。摘出した涙囊部の腫瘍は，核異型を伴う扁平上皮様の腫瘍細胞が充実性胞巣を形成し，特殊染色で粘液産生細胞の混在があり，悪性度が高い粘液表皮癌と判断した。耳前部の腫瘍はその組織像からリンパ節転移と判断した。その2週間後に顎下リンパ節郭清術を行った。さらに放射線照射を行い，初診から17か月後の現在まで小康状態にある。急性炎症の既往がない涙囊部腫瘤では涙囊腫瘍の可能性があることを示す症例である。

　A 72-year-old woman developed a tumor nasal to the right medial canthus 15months before. She had been treated as chronic dacryocystitis ever since. She was referred to us after detection of a tumorous lesion by computerized tomography（CT）. She showed painless tumors in the right lacrimal sac and preauricular regions. By radiography,the tumor had invaded the ethmoidal sinus with positive⁶⁷Ga uptake. Surgically excised lacrimal sac tumor showed epidermoid cells with atypical nuclei forming solid sheets. Mucin-secreting cells were also present,leading to the diagnosis of high-grade mucoepidermoid carcinoma. The preauricular tumor was interpreted as matasatic from the lacrimal sac. She later underwent radical excision of submaxillary and cervical lymph node metastases followed by external irradiation. She has been doing well until 17months after her initial visit. This case illustrates that lacrimal sac tumor has to be differentiated from chronic dacryocystitis in the absence of acute inflammation.